PLATE 6

Fig. 1. Adult male of Hypopachus caprimimus from Tuxpan, Michoacán. × 2-1/2.

Fig. 2. Adult male of Hypopachus oxyrrhinus ovis from Tangamandapio, Michoacán. × 3.

4. A distinct, pale-colored, diagonal lateral stripe is found in females only from localities outside of the Balsas-Tepalcatepec Basin; females from the basin have a spotted dorsum.

5. Males from the Balsas-Tepalcatepec Basin usually have a broad middorsal line that is yellow or pale tan; those from outside the basin have either a narrow middorsal line or none.

6. Males from the Balsas-Tepalcatepec Basin have low, scattered dorsal tubercles (Fig. 3); males from outside the basin have a concentration of tubercles in a broad band on the back (Fig. 4).

Therefore the nature of the cranial crests is of little value in separating two populations, but the color pattern of the females and the nature of the dorsal tubercles of the males do show distinct differences. Furthermore, certain differences in size and proportion are evident; Bufo marmoreus is a slightly larger toad and has a relatively longer tibia and longer head than perplexus (Table 2).

Table 2.—Comparison of Certain Measurements and Proportions in Bufo marmoreus and B. perplexus. (Means Are Given in Parentheses Below the Ranges.)

Tibia lengthHead length
Species Sex NSnout-vent length Snout-vent lengthSnout-vent length
B. marmoreus ♂1561.5-72.5 35.9-41.6 28.3-33.3
(65.2) (39.0) (31.6)
B. perplexus ♂2050.0-59.0 33.7-38.1 26.4-31.1
(54.9) (36.4) (29.5)
B. marmoreus♀ 768.0-76.0 33.0-36.8 26.8-32.6
(70.7) (34.7) (29.6)
B. perplexus♀ 664.1-69.8 32.4-36.9 25.1-29.0
(66.8) (35.5) (27.5)

Taylor (1943a:347) described Bufo perplexus from Mexcala on the Río Balsas in Guerrero. Among the many paratypes are specimens from Tonolá, Chiapas, and Tehuantepec, Oaxaca. These apparently were referred to perplexus solely on the nature of the cranial crests. All of the specimens examined during the course of the present study from the lowlands of Veracruz and from the Pacific lowlands from Sinaloa southward to Chiapas are referable to Bufo marmoreus; those from the Balsas-Tepalcatepec Basin are referable to Bufo perplexus, as defined above. Ten specimens from Chilpancingo, Guerrero (UMMZ 115352), do not readily fit either species. Perhaps there is gene exchange between the inland and coastal populations through the relatively low pass at Chilpancingo, at the mouth of the Río Balsas, and near the convergent headwaters of the Río Coahuayana and Río Tepalcatepec in southern Jalisco. If this can be demonstrated, then Bufo perplexus would have to be considered as a subspecies of Bufo marmoreus, instead of an allopatric species.

Bufo perplexus Taylor

Bufo perplexus Taylor, Univ. Kansas Sci. Bull., 29:347, October 15, 1943.—Balsas River near Mexcala, Guerrero, México.

Aguililla (2); Apatzingán (42); Buena Vista (5); Capirio (3); La Playa (25); Lombardia (6); Nueva Italia (9); Río Cancita, 14 km. E of Apatzingán; Río Tepalcatepec, 27 km. S of Apatzingán; San Salvador (4); Tzitzio; Volcán Jorullo.

Bufo occidentalis Camerano

Bufo occidentalis Camerano, Atti R. Accad. Sci. Torino, 14:887, December 31, 1878.—México. Type locality restricted to Guanajuato, Guanajuato, México, by Smith and Taylor (1950a:330). Firschein, Copeia, no. 3:220, September 15, 1950.

Bufo símus, Smith and Taylor, Bull. U. S. Natl. Mus., 194:42, 1948.

Barranca Seca (32); Cerro de Barolosa (4); Cerro Tancítaro, 3 km. E of Apo (2); Cerro Tancítaro, 19 km. E. of Apo (10); Charapendo; Coalcomán (7); Dos Aguas (4); Jacona, Jaramillo (2); Las Tecatas; Los Reyes (181); Tancítaro (10); Uruapan (3).

This toad is an inhabitant of pine and oak forests between 900 and 2400 meters. Near Charapendo on the slopes of the Sierra de los Tarascos and at Coalcomán it apparently reaches its lowest altitudinal limits. At both of these localities the pine-oak forest is replaced by arid tropical scrub forest on the lower slopes.

Twenty-four tadpoles were collected on May 3 in a quiet section of a fast stream near Barranca Seca. The tadpoles have a robust body, broadest about two-thirds the distance from the snout to the posterior edge of the body, half again as broad as deep. Eyes dorsolateral; nostrils dorsal, somewhat directed forward, and about three-fifths the distance from the tip of the snout to the eye; spiracle sinistral and lateral, located at about midbody; anus median; tail long and slender; tail-musculature extends nearly to tip of tail; depth of tail-musculature at mid-length about one-third total depth of tail; dorsal tail-fin not extending onto body (Fig. 5); average body length of ten tadpoles having small hind limb buds, 14.4 mm.; average tail length, 22.0 mm.

Mouth ventral, nearly terminal, about one-third as wide as widest part of body; anterior lip has no papillae; lower lip bordered by two rows of papillae and lateral lips by one row of papillae; beaks moderately well developed, the upper forming a broad arch and finely denticulate; tooth rows 2/3, the upper rows extending to the edge of the lips, subequal in length, and slightly longer than lower rows, which also are subequal in length; inner upper tooth row broken medially; inner lower tooth row sometimes broken (Fig. 6).

The body is black dorsally and laterally, and bluish gray ventrally; the tail musculature is brown and stippled with darker brown. The fins are transparent and stippled with brown, the stippling being most pronounced on the posterior two-thirds of the upper tail-fin.

Fig. 5. Tadpole of Bufo occidentalis (UMMZ 94269) from Barranca Seca, Michoacán. × 3.

Fig. 6. Mouthparts of larval Bufo occidentalis (UMMZ 94269) from Barranca Seca, Michoacán. × 20.

Forty recently metamorphosed individuals average 18.9 mm. in snout-vent length.

The relationships of this toad seem to be with Bufo bocourti Brocchi, an inhabitant of pine and oak forests in the uplands of Chiapas and Guatemala. In Bufo occidentalis the tympanum usually is indistinct and sometimes completely covered, and it is absent in bocourti. Bufo occidentalis has a broader interorbital area and relatively shorter and more rounded parotid glands than bocourti. The tadpoles of the two species are nearly identical (see Stuart, 1943:12).

Leptodactylus labialis (Cope)

Cystignathus labialis Cope, Proc. Amer. Philos. Soc., 17:90, 1877.—No type locality designated; type locality restricted to Potrero Viejo, Veracruz, México, by Smith and Taylor (1950a:350).

Leptodactylus labialis, Brocchi, Mission Scientifique au Mexique et dans l'Amerique Centrale, pt. 3, sec. 2, livr. 1:20, 1881.

Apatzingán (26); Capirio (5); Cofradía (9); El Sabino (4); Lombardia; Río Tepalcatepec, 27 km. S of Apatzingán (2).

In the Tepalcatepec Valley this frog reaches the northernmost known limit of its range in western México. Although the species is abundant in the valley, it apparently is absent from the coastal lowlands. In the Tepalcatepec Valley Leptodactylus melanonotus seems to be more abundant than labialis. In the rainy season both species have been heard calling from the same ponds and flooded fields.

There are only slight differences in size between the sexes; measurements of 20 males and eight females are, respectively: snout-vent length, 32.3-39.5 (35.1), 34.1-39.2 (37.2); tibia length, 14.3-17.0 (15.4), 14.9-16.8 (15.8); head width, 11.0-13.6 (12.0), 12.2-13.2 (12.6); head length, 12.8-15.1 (13.3), 12.8-14.6 (13.7).

Leptodactylus melanonotus (Hallowell)

Cystignathus melanonotus Hallowell, Proc. Acad. Nat. Sci. Philadelphia, 12:485, 1861.—Nicaragua. Type locality restricted to Recero, Nicaragua, by Smith and Taylor (1950a:320).

Leptodactylus melanonotus, Brocchi, Mission Scientifique au Mexique et dans l'Amerique Centrale, pt. 3, sec. 2, livr. 1:20, 1881.

Apatzingán (103); Capirio; Charapendo (7); Coahuayana; Cofradía (10); El Sabino (21); La Playa (3); Lombardia (5); Maruata; Nueva Italia (7); Ostula (9); Playa Azul (11); Río Marquez, 10 km. S of Lombardia; Río Marquez, 13 km. SE of Nueva Italia (6); Río Tepalcatepec, 27 km. S of Apatzingán.

This species is widespread in the lowlands of the state; it has been collected up to elevations of 1050 meters in the Tepalcatepec Valley. In the dry season individuals were discovered beneath rocks along streams and in damp arroyos; in the rainy season they were found wherever there was water. Males were heard calling from flooded fields, ditches, rocky streams, and small puddles. The call is a series of individual notes: "woink, woink, woink."

Adult males are noticeably smaller than females; measurements for 20 males and ten females from Apatzingán are, respectively: snout-vent length, 29.6-34.6 (32.3), 36.3-44.1 (40.8); tibia length, 12.6-15.1 (14.0), 16.5-19.0 (17.8); head width, 10.8-11.9 (11.3), 12.6-14.8 (13.7); head length, 11.2-13.2 (11.9), 13.1-14.8 (14.0). Brownish yellow ventral glands are present in some juveniles and in some adults collected in the dry season as well as in the rainy season.

Leptodactylus occidentalis Taylor

Leptodactylus occidentalis Taylor, Trans. Kansas Acad. Sci., 39:349, 1937.—Tepic, Nayarit, México.

Five km. W of Tangamandapio.

On the night of June 11, 1958, this species was calling from a hyacinth-choked ditch. Although numerous individuals were heard, only one specimen was obtained. The frogs were calling from the tangled mat of hyacinths along with Hyla eximia, Hypopachus oxyrrhinus ovis, and Rana pipiens.

Taylor (1936a:352) characterized this species as follows: "The narrow head, small maximum size (38 mm. for females, 33 mm. for males), the character of the postaxillary and postfemoral glands, the narrower groups of vomerine teeth, clearly distinguish this western Mexican form from the more robust, larger melanonotus to the south. The call is likewise fainter and different in quality." Concerning the glands, Taylor (loc. cit.) remarked: "There is a possibility that the horny excrescence covering the glands may appear only during the breeding season. This character is quite as strongly marked in females as in males." Bogert and Oliver (1945:324) concluded that the population of Leptodactylus in northwestern México could not be distinguished from melanonotus in other parts of the country and thus synonymized Leptodactylus occidentalis with melanonotus. Bogert and Oliver (op. cit.: 324) stated that the extent as well as the presence or absence of ventral glands was highly variable in all samples examined by them.

Upon seeing numerous living individuals of Leptodactylus melanonotus from many parts of its range in México and individuals of the population of Leptodactylus in northwestern México (Nayarit and Sinaloa), I was immediately impressed not so much by the differences in the development of the ventral glands, but by the color of the glands. The differences in color are apparent in freshly preserved specimens. With the exception of Leptodactylus from northwestern México, specimens of melanonotus from throughout México and northern Central America have yellow or yellowish brown glands. Specimens from northwestern México have black or brownish black glands that are conspicuously darker than those found in melanonotus. Examination of 653 preserved specimens of Leptodactylus melanonotus from México and Guatemala has failed to reveal specimens with black ventral glands, like those found in specimens from northwestern México, to which the name Leptodactylus occidentalis has been applied. Furthermore, in melanonotus the glands are less distinct and more extensive than in occidentalis; in the latter species glands are absent from the throat and midventral area, where they often are present in melanonotus (Fig. 7).

In some individuals of both species collected in the dry season and in some collected in the rainy (breeding) season the glands are absent; the development of these glands, therefore, does not seem to be correlated with breeding. Likewise, the glands are present or absent in either sex, and often as not they are present in juveniles. Presence of the glands, therefore, cannot be correlated either with sexual or ontogenetic development. Since the glands are found in individuals from all parts of the range, it is unlikely that there is a correlation between the development of the glands and the environment.

Fig. 7. Diagrammatic view of ventral surfaces of Leptodactylus melanonotus (A) and Leptodactylus occidentalis (B), showing usual position and size of glandular areas. Approx. natural size.

Aside from the differences in the ventral glands, the call is different in the two populations. The call of Leptodactylus occidentalis is a rather harsh "wack, wack, wack" as contrasted with the more nasal "woink, woink, woink" of melanonotus. Sound spectrographs are needed to analyze the differences in calls. None of the specimens of occidentalis examined approaches in size the largest individuals of melanonotus; possibly the size of the frogs is another valid character for separating the species. On the basis of the above data it is evident that the frogs in northwestern México show certain characters that distinguish them from Leptodactylus melanonotus, as it is known throughout the rest of México. It is not known for certain that melanonotus and occidentalis are sympatric. Several series of old, poorly preserved specimens from Nayarit and Sinaloa cannot be placed in either species, for none has visible ventral glands. Leptodactylus melanonotus is known from Acaponeta, Nayarit (AMNH 43913-25), and the following localities in Jalisco: Barro de Navidad (UMMZ 118098), La Concepción (UMMZ 113081), La Resolana (UMMZ 102104), and Tenachitlán (UMMZ 113045-6). Records for Leptodactylus occidentalis are: Álamos, Sonora (AMNH 51356-65); Culiacán (AMNH 49511-9), Chele (UMMZ 110914), and Rosario (UMMZ 113062) in Sinaloa; Ixtlán del Río (UMMZ 102108), San Blas (UMMZ 112814, 112994, 110892, 115543), and Tepic (UMMZ 115544) in Nayarit; Ameca (UMMZ 102106-7) and La Cofradía on the south shore of Lago de Chapala (UMMZ 102105) in Jalisco; and Tangamandapio, Michoacán (UMMZ 119145). From these scattered records it appears that Leptodactylus occidentalis in the southern part of its range stays in the uplands, whereas melanonotus is confined to the lowlands.

Microbatrachylus hobartsmithi (Taylor)

Eleutherodactylus hobartsmithi Taylor, Trans. Kansas Acad. Sci., 39:355, 1937.—Uruapan, Michoacán, México.

Microbatrachylus hobartsmithi Taylor, Univ. Kansas Sci. Bull., 26:501, November 27, 1940.

Cascada Tzararacua (6); 21 km. W of Ciudad Hidalgo; 29 km. E of Morelia; Puerto Hondo; San José de la Cumbre (13); Uruapan (2); Zitácuaro.

Of six specimens from Cascada Tzararacua, five are colored like typical M. hobartsmithi, having the anterior and posterior surfaces of the thighs and the upper arms pale pink in life and a grayish brown dorsum in preservative. The other specimen (UMMZ 94231) has in preservative a dark brown dorsolateral line on each side enclosing a pale tan area that extends from the snout to the vent. One specimen from 29 kilometers east of Morelia (UIMNH 40338) and 13 specimens from San José de la Cumbre (UMMZ 102111) do not have the prominent tarsal tubercles characteristic of M. hobartsmithi. Also, in these fourteen specimens the palmar tubercles are larger, and the dark anal patch more distinct, than in typical M. hobartsmithi. Possibly these specimens, which are from the high mountains in the eastern part of Michoacán, represent another species of Microbatrachylus. However, Taylor (1940d:501) reported a series of M. hobartsmithi from the mountains 10 miles west of Villa Victoria in the western part of the state of México.

The largest specimen from Michoacán is a gravid female (UIMNH 16104) having a snout-vent length of 23.5 mm.

Microbatrachylus hobartsmithi has been found in rocky ravines along streams in the Cordillera Volcánica and the southwestern escarpment of these mountains at elevations from 1450 to 2750 meters.

Microbatrachylus pygmaeus (Taylor)

Eleutherodactylus pygmaeus Taylor, Trans. Kansas Acad. Sci., 39:352, 1937.—1 mile north of Rodriguez Clara, Veracruz, México.

Microbatrachylus pygmaeus Taylor, Univ. Kansas Sci. Bull., 26:500, November 27, 1940.

Microbatrachylus albolabris Taylor, Univ. Kansas Sci. Bull., 26:502, November 27, 1940.—2 miles west of Córdoba, Veracruz, México.

Microbatrachylus minimus Taylor, Univ. Kansas Sci. Bull., 26:507, November 27, 1940.—Agua del Obispo, Guerrero, México.

Microbatrachylus imitator Taylor, Univ. Kansas Sci. Bull., 28:70, May 15, 1942.—La Esperanza, Chiapas, México.

Arteaga (328).

This large series (UMMZ 119247-8) was collected on June 22 and 23, 1958, before the onset of the heavy summer rains. The frogs were found in a shaded ravine at the north edge of Arteaga; they were obtained during the day, at which time they were actively moving about in the leaf litter along a small stream.

These frogs are all referred to M. pygmaeus, because this is the earliest name available for frogs showing the variation in characteristics displayed by this large series. The characters used by Taylor (1936a, 1940d, 1941a, and 1942b) and Smith and Taylor (1948) to distinguish the various species of Microbatrachylus include color pattern, relative length of the hind limb, presence and position of dorsal dermal folds or pustules, relative size of inner and outer metatarsal tubercles, and the number of palmar tubercles. All specimens from Arteaga have two palmar tubercles; the inner and outer metatarsal tubercles are subequal in size. Furthermore, aside from sexual difference, there is little variation in the relative length of the hind limbs (Table 3). However, many color patterns do exist in the series; each of these color patterns is described below.

Table 3.—Snout-vent Length Expressed as a Percentage of Tibia Length in Animals of Six Color Patterns of Microbatrachylus pygmaeus. (Letters Refer to the Variants Having the Color Pattern Discussed Immediately Below)

Color PatternSexNumberof specimensRange of variationMeanTwice standard error of mean
A ♂ 2551.4-57.555.2 3.34
♀ 2549.3-54.951.6 3.12
B ♂ 2051.0-57.155.4 2.44
♀ 2147.3-54.951.2 3.52
C ♂ 654.5-56.255.2 ....
♀ 650.0-52.951.6 ....
D ♂ 1752.9-58.255.4 2.64
♀ 1448.5-56.652.1 4.16
E ♂ 1050.9-56.955.1 3.40
♀ 749.6-54.551.6 ....
F♀ 251.9-52.652.3 ....

A.—225 specimens: Dorsum mottled brown and cream, usually with a dark spot between the eyes and one or two dark V-shaped marks with the apex anteriorly on the back; 55 of these have a narrow cream-colored line from the tip of the snout to the vent and thence onto the posterior surfaces of the thighs. All are pustulate above; in most specimens the pustules form no pattern, but in some they tend to form a V in the scapular region.

B.—41 specimens: Dorsum pale tan or cream-color with brown mottling on flanks; a brown interorbital bar and a brown chevron in scapular region. Dorsum irregularly pustulate; in some specimens the pustules tend to form a V in the scapular region.

C.—12 specimens: Dorsum colored like "A", but having a broad yellow stripe narrowly bordered by black from the tip of the snout to the vent; in some specimens there is a narrow yellow stripe on the posterior surfaces of the thighs. The dorsum is irregularly pustulate.

D.—31 specimens: Dorsum variably streaked with cream-color or pale tan and brown; usually a broad cream-colored stripe from eyelid to groin bordered laterally by a somewhat narrower brown stripe; middorsal area cream-color and separated from dorsolateral cream-colored stripe by a brown stripe, or middorsal area brown with a cream-colored or yellow, narrow stripe from tip of snout to vent; a dark stripe from tympanum to flank; dorsal surfaces of heels creamy white to pale orange; anal patch brown. A dermal ridge from posterior edge of eyelid to rump; another ridge extends posteromedially from the eyelid; scattered pustules on the dorsum in some specimens.

E.—17 specimens: A narrow dark stripe from snout, through nostril and eye, over tympanum, to vent, enclosing a unicolor dorsum (reddish tan to yellowish tan in life); heels pale tan or yellow above; anal patch black. A faint dermal ridge from posterior edge of eyelid to rump, or part way to rump.

F.—2 specimens: Mottled brown and cream-color above; upper lips and upper arms white. A dermal fold from posterior edge of eyelid to rump; scattered pustules on dorsum.

Some of these color variants are assignable to names proposed by Taylor: "A" and "B" undoubtedly are M. pygmaeus (Taylor, 1936a); "C" probably is M. pygmaeus; "D" is referable to M. minimus (Taylor, 1940d) in most characteristics, although the coloration is more nearly like that of M. lineatissimus (Taylor, 1941a), a larger species characterized by a relatively long hind limb; "E" apparently is M. imitator (Taylor, 1942b); "F" is M. albolabris (Taylor, 1940d). Examination of series of these frogs from other parts of México shows a similar composition of color variants. Of 78 specimens from the Río Sarabia and the village of Sarabia in Oaxaca (UMMZ 115428-37), 57 are "A," six are "D," three are "E," and 12 are "F"; of 22 specimens from Teapa, Tabasco (UMMZ 113829), 11 are "A," five are "D," two are "E," and four are "F"; of 33 specimens from Potrero Viejo, Veracruz (USNM 115447-58, 115461-71, 116840-2, 116864-70), ten are "A," 13 are "E," and ten are "F"; of 31 specimens from La Esperanza, Chiapas (USNM 115477-9, 116827-39, 116849-63), 28 are "A" and four are "F."

It is highly doubtful if these color variants are actually distinct species. Goin (1950 and 1954) in his studies of inheritance of color pattern in West Indian species of the genus Eleutherodactylus has shown that similar color pattern variants come from the same clutch of eggs; furthermore, Goin has worked out the genetic ratios of certain of these variants. Heathwole (in litt.) obtained "normal" specimens and individuals having a broad middorsal stripe ("C" in figure 9) from a clutch of eggs of Eleutherodactylus gollmeri. The presence of a broad middorsal yellow stripe is common in Eleutherodactylus rugulosus.

Perhaps the most interesting aspect of variability in color pattern in Mexican eleutherodactylids is the parallelism between members of the Eleutherodactylus rhodopis-group and some members of Microbatrachylus. In the former group there are white-lipped individuals (Eleutherodactylus beatae Boulenger), individuals having a unicolor reddish or yellowish dorsum (E. dorsoconcolor Taylor), and individuals having a dorsal pattern of irregular longitudinal brown and cream-colored streaks (E. venustus Günther). In the humid forests of southern Veracruz, northern Oaxaca, and Chiapas members of both groups occur sympatrically. A proper understanding of the evolutionary significance of these variants in the two groups, as well as proper allocation of the presently recognized species, must await experimental evidence based on studies of the inheritance of color pattern. Nevertheless, at present it is apparent that certain characters, especially the nature of the dermal folds and pustules, and the color pattern, are of little taxonomic value in distinguishing "species" of Microbatrachylus. The data derived from a study of the large series from Arteaga, together with that from the other series examined, suggests that Microbatrachylus albolabris, imitator, minimus, and pygmaeus are morphotypes of one species. Of these names, pygmaeus is the oldest. Consequently Microbatrachylus pygmaeus has been used here for the series from Arteaga.

Although Microbatrachylus hobartsmithi, a species distinguished from all of the above by the presence of tubercles on the outer edge of the tarsus, is known from Michoacán northward into Nayarit, Microbatrachylus pygmaeus previously has not been known north of Guerrero, where it occurs in habitats similar to that in which it was collected at Arteaga.

Eleutherodactylus augusti cactorum Taylor

Eleutherodactylus cactorum Taylor, Univ. Kansas Sci. Bull., 25:391, July 10, 1939.—20 miles northwest of Tehuacán, Puebla, México.

Eleutherodactylus augusti cactorum, Zweifel, Amer. Mus. Novitates, 1813:20, December 23, 1956.

Cherán; Coalcomán; Uruapan.

The few specimens indicate that this species occurs at moderate to high elevations in the state. The specimens from Cherán and Uruapan were obtained in pine forests; the specimen from Coalcomán was found on a rocky hillside covered with dense forest and located about 100 meters below the lower limits of the pine forest in the area. A specimen from Rancho Reparto (elevation 1850 meters) on the west slope of Cerro Barolosa was lost.

The specimen from Coalcomán (UMMZ 104728) is a juvenile having a snout-vent length of 25.0 mm. In life it was tan above, mottled with olive-green. The ventral surfaces were gray; the hind limbs were distinctly barred with yellow and brown, and the lips were barred with yellow and black.

Eleutherodactylus occidentalis Taylor

Eleutherodactylus occidentalis Taylor, Proc. Biol. Soc. Washington, 54:91, July 31, 1941.—Hacienda El Florencio, Zacatecas, México.

Arteaga (2); Cascada Tzararacua; Coalcomán (2); 19 km. SW of Coire (3); La Placita (7); Los Reyes; Ostula (4); Pómaro (2).

The locality records for this species suggest that it is a member of a group of animals, the distribution of which includes the western part of the Mexican Plateau and the Pacific lowlands. In Michoacán this frog has been collected in pine-oak forest at Cascada Tzararacua and at Los Reyes, in arid scrub forest at Arteaga and Coalcomán, and in tropical semi-deciduous forest on the lower Pacific slopes of the Sierra de Coalcomán. On July 5, 1950, James Peters (1954:6) found calling males at La Placita.

Most of the specimens are immature; four adult males have snout-vent lengths of 30.9-33.0 (32.2) mm. In all specimens the first finger is noticeably longer than the second; the inner metatarsal tubercle is large, flat, and cream-colored, contrasting with the dark brown sole of the foot. When the hind limbs are adpressed, the heels broadly overlap. Characteristically, a dark line extends from the snout, through the eye, above the tympanum, to a point above the insertion of the forelimb. Usually there is a dark bar behind the tympanum, two dark brown bars from the eye to the mouth and thence onto the lower jaw, and another dark bar on the upper lip between the eye and nostril. One adult from Arteaga, an adult and a juvenile from La Placita, and one juvenile each from Coire, Ostula, and Pómaro, have the lower lip barred with dark brown and white, and have a white stripe extending the length of the upper lip. In life the dorsum varies from dark gray or olive-brown to tan or reddish brown.

This species belongs to a group containing two other populations that are currently recognized as species—calcitrans, known only from Omiltemi, Guerrero, and mexicanus, reported from the mountains of Oaxaca. Another apparently undescribed member of this group has been collected in the mountains of northern Puebla. The locality records indicate that the group inhabits the mountains on the periphery of the Mexican Plateau, except in western México, where Eleutherodactylus occidentalis extends to the Pacific lowlands.

Eleutherodactylus rugulosus vocalis Taylor

Eleutherodactylus vocalis Taylor, Univ. Kansas Sci. Bull., 26:401, November 27, 1940.—Hacienda El Sabino, Michoacán, México.

Arteaga (10); El Sabino (8); Salitre de Estopilas (3); Tumbiscatio (2); Tzitzio (2).

The distributional data on this frog in Michoacán indicate that it inhabits riparian situations in arroyos and canyons in the lower slopes of the Cordillera Volcánica and the Sierra de Coalcomán, where it has been taken at elevations only below 1100 meters.

The dorsal color of living individuals from Arteaga varied from dark gray and olive brown to tan and reddish brown. The iris was grayish brown. In contrast, individuals from Agua del Obispo, Guerrero, had pale golden eyes; specimens from Matías Romero, Oaxaca, had gold eyes heavily flecked with gray; and individuals from Volcán San Martin, Veracruz, had bronze eyes.

The use of the trinomial here is arbitrary. Frogs of the Eleutherodactylus rugulosus group in México (rugulosus, avocalis, and vocalis) exhibit only slight differences in size, proportions, and coloration (Duellman, 1958c:6). Furthermore, the named populations are allopatric. Eleutherodactylus rugulosus vocalis, as defined by Duellman (loc. cit.), occurs in the foothills of the Sierra Madre Occidental and associated ranges from central Sinaloa southward into Michoacán.

Tomodactylus angustidigitorum Taylor

Tomadactylus angustidigitorum Taylor, Univ. Kansas Sci. Bull., 26:494, November 27, 1940.—Quiroga, Michoacán, México.

Angahuan (6); Apo; Carapan (21); 19 km. S of Carapan (13); Cerro Tancítaro (12); Cherán; Corupu (14); Cuseño Station (14); Opopeo (3); Paracho (11); Parícutin (2); Pátzcuaro (3); Quiroga (59); San Juan de Parangaricutiro (16); Tancítaro (25); Uruapan (8); Zacapu (11).

This species is indigenous to the pine-oak forests on the southern rim of the Mexican Plateau, and has been collected at elevations from 1500 to 2500 meters. Males have been observed to call from rocks, rock fences, clumps of grass, and low bushes; the call is a single "peep." At San Juan de Parangaricutiro numerous specimens were found in the daytime beneath adobe bricks and lava on the volcanic ash derived from Volcán Parícutin; at Paracho individuals were found by day beneath rocks in a pine forest.

In most specimens the dorsum is dark reddish brown, and the prominent inguinal glands are cream-color or pale orange (Pl. 3, Fig. 1). Of eight individuals collected at Paracho, one was reddish brown, two were pinkish tan, three were dark brown, and two were black.

Tomodactylus fuscus Davis and Dixon

Tomodactylus fuscus Davis and Dixon, Herpetologica, 11:157, July 15, 1955.—1.5 miles southeast of Huitzilac, Morelos, México.

Los Cantiles (2); 28 km. E of Morelia.

The range of this species includes the Sierra Ajusco in México and Morelos and thence westward to the Serranía Ucareo in Michoacán. The specimen from 28 kilometers east of Morelia was found in an oak forest on a steep hillside at an elevation of 2100 meters. One from Los Cantiles was calling from a steep cliff at an elevation of 2200 meters in pine-oak forest. This specimen (UMMZ 119156) in life had a pale olive-brown dorsum with irregular dark brown mottling and transverse bars on the limbs. The interorbital bar, the upper arms, and the tips of the dorsal pustules were pale orange; the iris was pale grayish gold (Pl. 3, Fig. 2).

Tomodactylus nitidus nitidus (Peters)

Liuperus nitidus Peters, Monats. Akad. Wiss. Berlin, p. 878, 1869.—Izúcar de Matamoras, Puebla, México.

Tomodactylus amulae Günther, Biologia Centrali-Americana, Reptilia and Batrachia, p. 219, April, 1900.—Amula, Guerrero, México.

Tomodactylus nitidus nitidus, Dixon, Texas Jour. Sci., 9:385, December, 1957.

Copuyo (15); Tuxpan (8); Tzitzio (11).

One specimen from Tzitzio (UMMZ 99155) was referred to Tomodactylus nitidus petersi by Dixon (1957:390). A re-examination of this specimen, and examination of ten others from the same locality (UMMZ 121571) reveals that the relatively small size of the tympanum and absence of dense ventral spotting place these specimens closer to T. nitidus nitidus than to T. nitidus petersi.

The specimens from Tuxpan (UMMZ 114303-4) had in life a gray to olive tan ground color with dark olive-green markings, bright yellow thighs with olive-green transverse bands, yellowish tan shanks with olive-green bars, yellow groin, white inguinal glands with black markings, grayish white belly with scattered brownish black spots in some specimens, and a deep golden iris (Pl. 4, Fig. 1). These specimens were found calling from bushes in a rocky field at an elevation of 1800 meters. The call is a high-pitched "pee-ee-eep."

Tomodactylus nitidus orarius Dixon

Tomodactylus nitidus orarius Dixon, Texas Jour. Sci., 9:392, December, 1957.—4.5 miles southwest of Tecolapa, Colima, México.

La Placita (3); Pómaro.

These specimens, referred to Tomodactylus petersi by Duellman (1954b:5), were included in T. nitidus orarius by Dixon (1957:392). Color notes based on living individuals from Tecolapa, Colima (UMMZ 114312 and 116922), are: gray above mottled with brown; venter dirty white; anterior and posterior surfaces of thighs bright yellow; iris pale golden (Pl. 4, Fig. 2). The call is a soft "braa" usually followed by three high notes: "braaa-eep-ee-eep." In Michoacán this subspecies has been found only in the coastal region and the lower foothills of the Sierra de Coalcomán, an area in which it replaces Tomodactylus nitidus petersi. This is the only Tomodactylus known to inhabit coastal lowlands.

Tomodactylus nitidus petersi Duellman

Tomodactylus petersi Duellman, Occ. Pap. Mus. Zool. Univ. Michigan, 560:5, October 22, 1954.—Coalcomán, Michoacán, México.

Tomodactylus nitidus petersi, Dixon, Texas Jour. Sci., 9:390, December, 1957.

Aguililla; Apatzingán (8); Cascada Tzararacua: Charapendo (5); Coalcomán (5); 18 km. E of Dos Aguas (6); El Sabino (5); La Playa (2); Jiquilpan; Uruapan (2); Volcán Jorullo; Zamora.

In life, specimens from Apatzingán (UMMZ 114308-9) varied in dorsal color from grayish tan to pale brown; the dorsal markings were olive green. The thighs and groin were yellowish orange; the iris was pale golden, and the vocal sac was purplish gray (Pl. 5, Fig. 1). Measurements for 13 adult males from the Tepalcatepec Valley are: snout-vent length, 21.9-26.8 (24.3); tibia length, 8.4-9.9 (9.3); head width, 7.2-9.2 (7.8); head length, 7.6-8.7 (8.2).

At Apatzingán and Charapendo in the Tepalcatepec Valley males were found calling from rocks and bushes in open arid tropical scrub forest. The call, a triple note "peep-ee-eep," is repeated once every 90 to 135 seconds. Tomodactylus nitidus petersi probably ranges throughout the Tepalcatepec Valley and surrounding foothills. Dixon (1957:392) referred the specimens from Zamora, Jiquilpan, and Uruapan to this subspecies. Uruapan is near the lower limits of the pine forest on the slopes of the Cordillera Volcánica; Zamora and Jiquilpan are on a low part of the Mexican Plateau southeast of Lago de Chapala.

Tomodactylus rufescens Duellman and Dixon

Tomodactylus rufescens Duellman and Dixon, Texas Jour. Sci., 11:78, March, 1959.—Dos Aguas, Michoacán, México.

Dos Aguas (14); 18 km. E of Dos Aguas (6).

Fourteen specimens from the pine-oak forests around Dos Aguas (UMMZ 118503-10, 121498-9) have reddish brown dorsal color and a narrow cream-colored middorsal line (Pl. 5, Fig. 2). Twelve of these specimens are adult males having snout-vent lengths of 20.7 to 24.6 (22.5) mm. One female has a snout-vent length of 24.8 mm., and one juvenile has a snout-vent length of 14.5 mm. Six specimens are from a region of mixture of pine-oak forest and arid tropical scrub forest at 18 kilometers east of Dos Aguas (UMMZ 121497, 121500). All are males having snout-vent lengths of 18.0 to 22.6 (20.7) mm. The dorsum is tan marked with black; the thighs are yellowish orange.

The specimens from 18 kilometers east of Dos Aguas were found on July 22, 1960, by Floyd L. Downs and John Winklemann, who collected calling males of Tomodactylus rufescens and Tomodactylus nitidus petersi at the same locality. Downs (personal communication) stated the call was a single note. At Dos Aguas I heard T. rufescens give two calls, one a single "peep," the other a triple note—"pee-ee-eep."

In the higher parts of the Sierra de Coalcomán Tomodactylus rufescens seems to fill the same niche as T. angustidigitorum does in the Cordillera Volcánica. At lower elevations in their respective mountain ranges the species occur sympatrically with T. nitidus petersi.

Diaglena reticulata Taylor

Diaglena reticulata Taylor, Univ. Kansas Sci. Bull., 28:60, May 15, 1942.—Cerro Arenal, Oaxaca, México.

Nueva Italia (3); Ostula (7).

Until recently frogs of the genus Diaglena were known only from a few specimens from southern Sinaloa (Diaglena spatulata) and from the Pacific lowlands of the Isthmus of Tehuantepec (Diaglena reticulata). Peters (1955a) reported specimens from Ostula, Michoacán, and compared these specimens with one D. reticulata from Tehuantepec, Oaxaca, and four D. spatulata from Sinaloa. This comparison showed that the specimens from Michoacán, although showing some minor differences from D. reticulata, are closer to that species than to D. spatulata. Subsequent to Peters' work, series of both species of Diaglena, including additional specimens from Michoacán and from Colima, have been collected, and a more qualified comparison is now possible.

In comparing specimens of D. spatulata from southern Sinaloa (UMMZ 115322) with specimens of D. reticulata from Tehuantepec, Oaxaca (UMMZ 115321), the differences noted by Taylor (1942c:60) were found to be constant. But specimens from Ostula, Michoacán (UMMZ 104418), and five individuals from Colima (TNHC 26379-83) were found to be intermediate in certain characters. The skin of the dorsum in D. reticulata is granular; that in D. spatulata is smooth. The skin in specimens from Ostula and Colima is slightly granular. The dorsal ground color of D. reticulata is yellowish brown with dark reticulations; the dorsal ground color of D. spatulata is olive-green. Specimens from Ostula and Colima most closely resemble those from Tehuantepec in coloration, but the reticulations are more coarse, and the ground color has an olive-green tint. Diaglena reticulata also differs from D. spatulata in having a larger over-all size, slightly broader head, a narrower interorbital distance, and a more pointed snout with a deeper labial shelf (Table 4). The specimens from Ostula and Colima are intermediate between D. reticulata from Oaxaca and D. spatulata from Sinaloa in body proportions.

Of three specimens from the Tepalcatepec Valley (JRD 5991-3), only two are suitable for measuring. These specimens are smaller than adults from the coastal areas and have broader heads and snouts, but narrower interorbital distances, than specimens in the other samples (Table 4). The texture of the skin is like that of specimens from Ostula and Colima. The coloration resembles that of D. reticulata, but the reticulations are bold and form indistinct bands on the hind limbs.

Table 4.—Comparison of Four Characters in Five Samples of Diaglena.
(All Data Are for Males; Means Given in Parentheses Below Ranges.)

Locality Number of
specimens		Snout-vent length Head widthInterorbital distanceInternarial distance
Snout-vent lengthHead width Head width
Oaxaca 971.1-87.525.4-29.163.0-71.4 11.9-13.8
(80.7) (27.9) (67.1) (12.9)
Coast of Michoacán 572.0-79.224.3-27.267.0-73.8 13.7-14.4
(74.8) (25.6) (71.4) (14.1)
Colima 471.7-79.626.1-28.670.5-75.3 16.0-17.9
(74.8) (27.4) (72.0) (16.6)
Tepalcatepec Valley 263.0-65.428.3-32.257.3-62.4 17.0-20.2
(64.2) (30.3) (59.9) (18.6)
Sinaloa 1171.9-81.324.0-27.370.5-78.1 15.0-17.3
(77.3) (25.7) (73.4) (16.1)

All specimens from Michoacán and Colima more closely approach Diaglena reticulata than D. spatulata. The acquisition of additional specimens, especially from the area between Sinaloa and Colima and from Guerrero, is necessary to determine the relationships among the various populations known at present. Both species of Diaglena inhabit tropical scrub forest; none has been found in the more humid and tropical semi-deciduous forests. Humid forest replaces the scrub forest in the lowlands of southern Nayarit and northern Jalisco; possibly this forest acts as a barrier to the distribution of Diaglena and thus serves as a divider between the ranges of D. spatulata to the north and D. reticulata to the south.

Pternohyla fodiens Boulenger

Pternohyla fodiens Boulenger, Ann. Mag. Nat. Hist., ser. 5, 10:326, 1882.—Presidio, Sinaloa, México.

Nueva Italia (2).

These specimens (JRD 5994-5) were found on the road near Nueva Italia during a heavy rain on the night of August 25, 1960, by James R. Dixon. Both are females having snout-vent lengths of 64.0 and 59.0 mm. They are typical of the species as it is known from Sinaloa, Nayarit, Jalisco, and Colima.

These specimens constitute the southernmost record for the species, which ranges in semi-arid habitats from southern Arizona southward along the Pacific lowlands of México to Colima and inland on the Mexican Plateau in Jalisco.

Phyllomedusa dacnicolor Cope

Phyllomedusa dacnicolor Cope, Proc. Acad. Nat. Sci. Philadelphia, 16:181, September 30, 1864.—Colima, Colima, México. Funkhouser, Occ. Pap. Nat. Hist. Mus. Stanford Univ., 5:37, April 1, 1957.

Agalychnis alcorni Taylor, Copeia, no. 2:31, June 2, 1952.—Río Tepalcatepec, 17 miles south of Apatzingán, Michoacán, México.

Agalychnis dacnicolor, Duellman, Herpetologica, 13:29, March 30, 1957.

Phyllomedusa alcorni, Funkhouser, Occ. Pap. Nat. Hist. Mus. Stanford Univ., 5:30, April 1, 1957.

Aguililla (13); Apatzingán (7); Charapendo; Coahuayana (3); Coalcomán (54); El Sabino; Huetamo Road (2); La Orilla; La Placita; Nueva Italia (4); 32 km. E of Neuva Italia (2); Río Cancita, 14 km. E of Apatzingán; Río Tepalcatepec, 27 km. S of Apatzingán; Salitre de Estopilas (2); Tzitzio (4).

This large tree frog has been found only in the lowlands below elevation of about 1000 meters, usually in arid tropical scrub forest. Calling males were heard on rainy nights throughout the rainy season; in nearly every instance both males and females were found in low trees and bushes. On summer nights when there had been no rain, adults were found sitting on bushes in the scrub forest.

At Coalcomán on July 1, 1955, a chorus was heard at midday. About forty Phyllomedusa dacnicolor were found in one guayava bush at the edge of a recently dried pond. Individual males were calling; clasping males were silent. The call is a barking groan. Fifteen individual egg masses were hanging from branches and leaves in tear-drop fashion. Each egg mass contained 100 to 350 pale green eggs, located only in the exterior part of the clear gelatinous mass. Two composite egg masses appeared to have been made up by egg deposition on the part of three to five females (Pl. 2, Fig. 2).

As shown by Duellman (1957a), the characters used by Taylor (1952) to diagnose Phyllomedusa alcorni are sexually dimorphic. Funkhouser (1957) apparently was unaware of this sexual dimorphism, for she recognized P. alcorni and P. dacnicolor as distinct species.

Phrynohyas inflata (Taylor)

Acrodytes inflata Taylor, Univ. Kansas Sci. Bull., 30:64, June 12, 1944.—La Venta, Guerrero, México.

Phrynohyas inflata, Duellman, Misc. Publ. Mus. Zool. Univ. Michigan, 96:19, February 1, 1956.

Phrynohyas corasterias Shannon and Humphrey, Herpetologica, 13:15, March 30, 1957.—4.8 miles east of San Blas, Nayarit, México.

Barranca de Bejuco.

One specimen of this large species was collected in 1951; it was found on a low branch in tropical semi-deciduous forest at an elevation of 65 meters. In life there were olive-gray blotches on a pale gray dorsum; the iris was a dark golden color.

This species, which is known from only a few specimens, seems to be restricted to the coastal lowlands and low foothills from Guerrero northward to Nayarit. Shannon and Humphrey (1957) described Phrynohyas corasterias from Nayarit. Their description was based on a small female having a snout-vent length of 34.4 mm. The new species was diagnosed as differing from P. inflata in having less webbing on the feet, a poorly developed supratympanic fold, a more pustulate dorsum, and marked differences in dorsal pattern, color, and nature of antebrachial banding. The significance of the webbing was questioned by Shannon and Humphrey. The nature of the supratympanic fold and dorsal pustules changes with age (Duellman, 1956a:31). Phrynohyas inflata is known to attain a snout-vent length of 95 mm. Dermal structures that undergo ontogenetic change are of little importance in comparing a juvenile with a large adult. The only significant difference in color pattern between P. inflata and P. corasterias is the presence of wide transverse bands on the limbs of the latter. In this respect P. corasterias approaches P. latifasciata, a species known only from two specimens from southern Sinaloa. The acquisition of additional specimens from Jalisco, Nayarit, and Sinaloa may show that P. inflata and P. latifasciata are conspecific, as suggested by Duellman (1956a:21). Nonetheless, the specimen on which the description of P. corasterias was based is not sufficiently different from the known specimens of P. inflata to warrant specific recognition.

Hyla arenicolor

Hyla arenicolor Cope, Jour. Acad. Nat. Sci. Philadelphia, ser. 2, 6:84, July, 1866.—Northern Sonora, México. Type locality restricted to Santa Rita Mountains, Pima County, Arizona, by Smith and Taylor (1950a:354).

Agua Cerca; Cascada Tzararacua (3); Chinapa; Cojumatlán; Dos Aguas; El Sabino (25); El Espinal; Lago de Camécuaro; Lombardia (2); Tupátaro; Zinapécuaro.

Altitudinally this frog ranges from 500 to 2100 meters; although the environments in which it has been found vary from open arid tropical scrub forest to pine forest, it usually is found near rocky streams in these habitats. There is great disparity in size between specimens from the mountains and those from the Tepalcatepec Valley. Seven males from elevations in excess of 1400 meters have an average snout-vent length of 34.7 mm.; nine from elevations below 1000 meters have an average snout-vent length of 49.1 mm. In life a male collected at night at Lombardia (UMMZ 112846) had dark brown spots on a grayish brown dorsum; the groin, anterior and posterior surfaces of the thighs, and ventral surfaces of the hind limbs and palms were yellowish orange. The belly and tips of digits were white; the vocal sac was purplish brown, and the iris was dark grayish gold. In contrast, a specimen obtained in the daytime at Chinapa (UMMZ 119204) had indistinct gray spots on a pale ashy gray dorsum; the flash colors were yellow. After dark the spots were dark olive-brown on a grayish brown dorsum.

Two males were found calling from a rocky stream near Lombardia on July 12, 1955. The call is a nasal "ah-ah-ah-ah."

Hyla baudini Duméril and Bibron

Hyla baudinii Duméril and Bibron, Erpétologie générale, vol. 8:564, 1841.—México. Type locality restricted to Córdoba, Veracruz, México, by Smith and Taylor (1950a:346).

Aguililla (5); Apatzingán (30); Arteaga; Buena Vista; Charapendo; Coahuayana; Cofradía (4); El Sabino (12); La Placita; La Playa; Maruata; Nueva Italia (3); 32 km. E of Nueva Italia (2); Ostula (4); Río Tepalcatepec, 25 km. S of Apatzingán (3); Salitre de Estopilas; San José de la Montaña (2); Tumbiscatio; Tzitzio.

This tree frog is widespread in the coastal lowlands and in the Tepalcatepec Valley up to elevations of about 1200 meters. It is found in numbers in the early part of the rainy season, at which time males were heard calling from bushes and trees along ditches and temporary ponds. The call is a loud nasal "waank-waank-waank." One individual that was emitting a long and unusually high-pitched call was found to have one hind limb engulfed by a Leptodeira maculata.

When active at night these frogs usually are pale tan to reddish brown above with dark brown markings. A specimen found sitting on a maguey plant in the daytime was pale ashy gray with a pale green upper lip.

Hyla bistincta Cope

Hyla bistincta Cope, Proc. Amer. Philos. Soc., 17:87, 1877.—Veracruz, México. Type locality restricted to Acultzingo, Veracruz, México, by Smith and Taylor (1950a:346).

Cerro San Andrés; Dos Aguas (2); Los Conejos (3); Uruapan (50).

In the Parque Nacional at Uruapan this species was found in abundance during the day. The frogs hide in an entanglement of vines and vegetation overhanging several small spring-fed streams. Tadpoles were in the rocky streams, and metamorphosing young were on vegetation at the edges of the streams.

In life the dorsum is greenish tan with brown mottling; in some individuals the entire dorsum is dark chocolate brown. The flanks are pale lemon yellow barred with lavender-brown. Notes on the color of a living frog from Dos Aguas (UMMZ 119193) are: Dorsal ground color a medium shade of brown with dark brown flecks; flanks black with silvery white and pale yellow spots; belly pale yellowish white; throat mottled with grayish brown; iris pale copper color.

Fig. 8. Tadpole of Hyla bistincta (UMMZ 115231) from Uruapan, Michoacán. × 2.

Description of Tadpole: Body somewhat depressed; maximum width of body slightly more than one-half of body length. Nostrils placed dorsolaterally and directed anteriorly, situated about midway between tip of snout and eye. Eyes of moderate size, dorsolateral in position and directed upwards. Tail about twice as long as body, thrice as long as deep, and tapering gradually to a rounded tip. Tail-musculature not extending to tip of tail fin. Spiracle sinistral, lateral, and situated at midbody. Vent dextral; the cloacal tube extending along ventral part of tail for a distance equal to about one-eighth of body length (Fig. 8). Average body length of six tadpoles with small hind limb buds, 19.5 mm.; tail length, 38.3 mm. Mouth ventral, its width equal to about two-thirds of greatest width of body. Lips bordered by two rows of small papillae; row of larger papillae between upper lip and outer upper tooth-row, similar row between lower lip and outer lower tooth-row; laterally these rows degenerating into numerous small papillae. Horny beaks well developed; upper beak moderately arched and deeply indented; lower beak slightly indented. Serrations of beaks blunt and peglike, moderately developed on both beaks, but slightly stronger on lower one. Tooth-rows 2/3; upper rows nearly equal in length and slightly longer than lower rows, which are subequal in length; inner upper tooth row interrupted medially by rounded notch; inner lower tooth-row turned downward laterally; teeth in all rows about equal in size, but decreasing in length laterally (Fig. 9).

Fig. 9. Mouthparts of larval Hyla bistincta (UMMZ 115231) from Uruapan, Michoacán. × 15.

Color in formalin: pale grayish brown dorsally and laterally; pale gray ventrally; tail-musculature brown; tail-fin translucent with scattered melanophores most numerous on upper fin.

In most details these tadpoles resemble those of Hyla robertsorum described by Rabb and Mosimann (1955).

Four metamorphosing young have snout-vent lengths of 23.0-23.5 (23.2); a completely metamorphosed individual has a snout-vent length of 24.8 mm.

In Michoacán this stream-breeding hylid occurs at elevations of 1,600 to 2,400 meters in the Sierra de Coalcomán and in the mountains rising from the Mexican Plateau.

Hyla eximia Baird

Hyla eximia Baird, Proc. Acad. Nat. Sci. Philadelphia, 7:61, October 20, 1854.—Valley of México. Type locality restricted to Coyoacán, Distrito Federal, México, by Smith and Taylor (1950a:329).

Hyla microeximia Maslin, Herpetologica, 13:81, July 10, 1957.—3 miles northwest of Jocotepec, Jalisco, México.

Ciudad Hidalgo (36); Cuitzeo; 29 km. NW of Jacona; Jiquilpan (2); Lago de Camécuaro (2); Lago de Pátzcuaro (129); Los Reyes; Morelia; Sahuayo (3); San Gregorio (63); Tangamandapio (4); Temazcal (26); Tupátaro; Tuxpan (15); Undameo (2); Uruapan (20); Zacapu; Zamora (27); Zinapécuaro (10).

More than 80 per cent of the specimens from Michoacán have brown spots between the lateral and dorsolateral dark stripes, and more than 50 per cent have spots between the dorsolateral stripes, at least posteriorly. In comparison with specimens from the Valley of México, those from Michoacán have more distinct dorsolateral stripes that extend farther anteriorly, sometimes to the eyelid, and in this respect are more nearly like those from Jalisco and Nayarit (Taylor, 1939b:425). Some specimens from the western part of Michoacán possess certain characters used by Maslin (1957:81) to distinguish Hyla microeximia from H. eximia; nevertheless, the variation is such that two species cannot be distinguished in Michoacán. Four series of freshly preserved specimens have been studied in detail; in the discussion below they are arranged from west to east; the measurement is for snout-vent length of ten males from each sample:

Zamora.—Twenty-two specimens (UMMZ 102083), 24.0-27.6 (26.1) mm. Dorsolateral dark stripe, or row of dashes, present in all specimens; dark spots in lateral and dorsal green fields; lateral dark stripe confluent with dorsolateral stripe posteriorly in 18 specimens; white line not extending to groin.

Temazcal.—Thirty-five specimens (UMMZ 119162), 26.5-31.1 (28.2) mm. Dorsolateral dark stripe of row of spots present only posteriorly in most; both dorsolateral stripes and dorsal spots lacking in four specimens; heavy spotting dorsally in three others; lateral and dorsolateral dark stripes confluent posteriorly in three; lateral white stripe extending to groin in 16 specimens.

Ciudad Hidalgo.—Thirty-six specimens (UMMZ 119163), 26.4-30.9 (28.2) mm. Dorsolateral dark stripe or row of spots present only posteriorly in most; no brown spots in the green fields of many specimens; large brown inguinal spot in most specimens; heavy spotting dorsally in four; lateral and dorsolateral dark stripes confluent posteriorly in five; lateral white line extending to groin in most specimens.

Tuxpan.—Fifteen specimens (UMMZ 115227), 28.7-33.0 (30.5) mm. Dorsolateral dark stripe or row of dashes in all specimens; dark spots in lateral green fields, at least posteriorly in most; dark spots posteriorly in the dorsal green field in five; lateral dark stripe separated from dorsolateral stripe in all specimens; lateral white line extends to the groin in all specimens.

As can be seen from the above descriptions, the distinguishing characters of Hyla microeximia—confluence of lateral and dorsolateral dark stripes posteriorly, extent of lateral white stripe, and distribution of dark spots dorsally—are found in individuals from all of the populations sampled. In the samples from western Michoacán there is a higher incidence of microeximia-like frogs than in those from other parts of the state. Hyla eximia is a wide-ranging species varying greatly geographically and individually. A thorough review of the species and related members of the Hyla eximia-group is necessary before certain populations can justifiably be segregated as subspecies or species.

In Michoacán Hyla eximia has been collected in mesquite-grassland, pine-oak forest, and cultivated areas on the Mexican Plateau from 1500 to 2300 meters; apparently it is absent from the Sierra de Coalcomán. This is the most abundant frog on the southern part of the Mexican Plateau; in the rainy season breeding choruses are found in temporary pools and in the marshes adjacent to the permanent lakes.

Hyla lafrentzi Mertens and Wolterstorff

Hyla lafrentzi Mertens and Wolterstorff, Zool. Anz., 84:235, August 25, 1929.—Desierto de los Leones, Distrito Federal, México.

Cerro San Andrés (26); Opopeo (9).

In March, 1949, James A. Peters collected this species at elevations of 2400 to 2800 meters on the west slope of Cerro San Andrés. The frogs were found beneath logs and rocks in a damp canyon in coniferous forest. Among the juveniles in this series is a completely transformed individual (UMMZ 102093) having a snout-vent length of 14.5 mm. Five adults have snout-vent lengths of 36.2-39.5 (38.0) mm. Hyla lafrentzi has noticeably longer hind limbs than H. eximia; in the former, when the hind limb is brought forward along the body, the tibiotarsal articulation extends to the snout. There are dark transverse bands on the hind limbs; the dorsolateral stripe is broken into an anterior and a posterior segment, and the latter is narrowly bordered by white in most specimens.

Hyla lafrentzi occurs at higher elevations than any other frog in Michoacán; the locality records from throughout the range indicate that it is restricted to pine and pine-fir forests. In these habitats it replaces Hyla eximia, which inhabits the lower pine-oak forests and mesquite-grassland on the Mexican Plateau. Ponds are absent at places where Hyla lafrentzi has been collected; possibly the eggs are laid in streams.

Hyla smaragdina Taylor

Hyla smaragdina Taylor, Copeia, No. 1:18, March 30, 1940.—6 kilometers east of Cojumatlán, Michoacán, México.

Hylella azteca Taylor, Proc. Biol. Soc. Washington, 56:49, June 16, 1943.—Tepoztlán, Morelos, México.

Cojumatlán (30); Copuyo (7); 18 km. E of Dos Aguas (22); Ostula (8); Pómaro (3); Sahuayo; Salitre de Estopilas (7).

Taylor (1940a:18) diagnosed this species as having few or no vomerine teeth, no vocal sac, a rather broad and flat head, two large tubercles below the anus, a granular venter, and a green dorsum in life. The specimens on which the description was based are either immature or non-breeding individuals; all were collected from bromeliads growing on cacti near Cojumatlán. Another small, flat-headed hylid from Tepoztlán, Morelos, was described and diagnosed by Taylor (1943b:49) as differing from Hyla smaragdina in having a vocal sac and a broader head. This specimen was named Hylella azteca. Specimens from the coastal region of Michoacán and Colima were referred to Hylella azteca by Peters (1954:7) and Duellman (1958c:8).

Comparison of topotypic Hyla smaragdina and the holotype of Hylella azteca (UIMNH 25044) with the several series of specimens from Michoacán has resulted in the conclusion that all pertain to only one species. Although the type series of Hyla smaragdina consists of immature specimens, the males in that series do possess vocal sacs. Since these were not breeding individuals, the sacs are not well developed. The characters of the anal tubercles and the relative width of the head are of no value in separating the two species. The apparently aestivating individuals comprising the type series of Hyla smaragdina, and the type of Hylella azteca, which also was found in a bromeliad, were green in life. Of the calling males found on the coast of Michoacán, most were yellowish tan when found; two were pale green, but soon changed to pale tan. Calling males from Copuyo and Dos Aguas were pale yellowish tan. Therefore the color of the dorsum is of little significance in distinguishing the two named populations.

Males of Hyla smaragdina have been found calling in the months of June and July from rocky streams; the call is a nasal "haah-haah-haah," repeated quickly and constantly for as long as 30 seconds. As pointed out by Duellman (1958c:9), this breeding behavior is unlike that suggested by Taylor (1943b:51). In Michoacán Hyla smaragdina has been found in tropical semi-deciduous forest, oak forest, and mesquite-grassland at elevations from 150 to 1500 meters.

Hyla smithi Boulenger

Hyla smithi Boulenger, Zool. Rec. Reptilia and Batrachia, 38:33, 1902.—Cuernavaca, Morelos, México.

Aguililla (14); Apatzingán (104); Arteaga; Charapendo (5); Coalcomán (11); El Sabino (44); La Playa (6); Lombardia (2); Nueva Italia (8); Playa Azul; Salitre de Estopilas (2).

This small hylid is abundant in the Tepalcatepec Valley to elevations of about 1000 meters; it was found infrequently on the coastal lowlands. Males call from bushes in and around flooded fields and ditches, from grasses and small herbs in the water and from vegetation overhanging small streams. The call consists of a series of short, high notes, somewhat reminiscent of a katydid's song. In the dry season occasional males were heard calling from irrigated fields near Apatzingán. In the daytime individuals were found in the axils of leaves of the elephant-ear plants (Xanthosoma).

In living individuals the dorsal color usually is uniform pale yellow; often the lateral white stripe is barely visible. The vocal sac is bright yellow, and the iris is pale gold. In some individuals there are scattered dark brown spots or flecks on the back and upper surfaces of limbs. Twenty males from Apatzingán have the following measurements: snout-vent length, 22.8-26.0 (25.0) mm., tibia length, 10.7-13.6 (12.6) mm.; head width, 7.2-8.0 (7.6) mm., head length, 7.1-8.1 (7.7) mm.

Hypopachus caprimimus Taylor

Hypopachus caprimimus Taylor, Univ. Kansas Sci. Bull., 26:526, November 27, 1940.—Agua del Obispo, Guerrero, México.

Buena Vista; Copuyo (6); Charapendo (3); Cofradía; Jaramillo; Jungapeo; San Salvador; Tuxpan.

Specimens of Hypopachus from the Balsas drainage in Michoacán have characters consistent with topotypic H. caprimimus. Eleven specimens from the southern edge of the Mexican Plateau all have the flanks darker than the dorsum, a distinct and continuous dark stripe from the occiput to the groin, a large dark spot in the inguinal region, and a pair of dark transverse stripes on the thigh and shank (Pl. 6, Fig. 1). With the exception of three specimens from Charapendo, all have a predominantly brown venter with round, cream-colored spots.

Peters (1954:8) referred specimens from Buena Vista and San Salvador to Hypopachus oxyrrhinus. He stated that the specimen (BMNH 1914.1.28.150) from San Salvador had flanks much darker than the dorsum and a well-defined continuous stripe from the occiput to the groin; this specimen has the characters of H. caprimimus. The specimen (BMNH 1914.1.28.151) from Buena Vista resembles H. oxyrrhinus in some characters, but it is not like H. oxyrrhinus ovis on the Mexican Plateau in Michoacán. The specimen has paired transverse stripes on the hind limbs as does H. caprimimus, and is here referred to that species.

In Michoacán this species has been collected in arid tropical scrub forest at elevations of 200 to 1800 meters in the northern foothills of the Sierra de Coalcomán, the Tepalcatepec and Tuxpan valleys, and on the lower slopes of the Cordillera Volcánica. Calling males have been found along streams. One specimen from Charapendo was regurgitated by a Leptodeira maculata.

Hypopachus oxyrrhinus ovis Taylor

Hypopachus ovis Taylor, Univ. Kansas Sci. Bull., 26:520, November 27, 1940.—Tepic, Nayarit, México.

Hypopachus oxyrrhinus ovis, Shannon and Humphrey, Herpetologica, 14:89, July 23, 1958.

Emiliano Zapata; 30 km. NW of Jacona (2); 10 km. NE of Pátzcuaro (2); Tangamandapio (16); 24 km. W of Zamora (16).

Thirty-seven specimens from the Mexican Plateau in northwestern Michoacán agree well with the diagnosis of Hypopachus oxyrrhinus ovis by Shannon and Humphrey (1958). With the exception of one specimen from Tangamandapio, all have dark bellies extensively mottled or spotted with cream-color. Most of the specimens have some form of an irregular, usually broken, dark line from the occiput to the groin. In eight specimens there is no line or linear arrangement of spots; instead the dorsum is spotted or flecked with dark brown. The ground color of the dorsum and flanks varies from dull reddish brown to grayish brown; cream-colored spots are evident on the flanks and posterior surfaces of the thighs in all specimens (Pl. 6, Fig. 2).

In comparison with 14 specimens from Quesería, Colima (UMMZ 80001-2), individuals from the Mexican Plateau have a darker venter with bolder markings, and a more mottled dorsum.

In Michoacán this species has been taken between 1500 and 2200 meters on the Mexican Plateau, where it inhabits mesquite-grassland and cultivated areas.

Rana dunni Zweifel

Rana dunni Zweifel, Copeia, no. 2:78, July 15, 1957.—Lago de Pátzcuaro, Michoacán, México.

Lago de Pátzcuaro (23); Río de Morelia, near Undameo (8).

Aside from the type series of this species, there are in the Museum of Zoology at the University of Michigan six specimens taken from "tanks" at the limnological station at Pátzcuaro by Paul S. Martin in 1948, and eight specimens found in shaded ditches along the Río de Morelia by Robert R. Miller on April 4, 1957. The Río de Morelia flows into Lago de Cuitzeo; this drainage is separated from Lago de Pátzcuaro by a chain of hills about 2400 meters in elevation. Dr. Richard G. Zweifel has examined these specimens and has informed me that, although they differ slightly from typical Rana dunni, they are much closer to that species than to Rana montezumae.

Rana megapoda Taylor

Rana megapoda Taylor, Univ. Kansas Sci. Bull., 28:310, November 12, 1942.—Chapala, Jalisco, México.

La Palma (8).

These specimens (USNM 113998-114005) are from the marshes along the southeastern shore of Lago de Chapala. Five females have snout-vent lengths of 124.0-138.1 (131.5), and one male has a snout-vent length of 110.2 mm. Two juveniles have snout-vent lengths of 49.7 and 56.3 mm. The coloration of the juveniles is more bold than that of the adults. The body proportions of these specimens agree with those presented by Zweifel (1957:80).

Rana montezumae Baird

Rana montezumae Baird, Proc. Acad. Nat. Sci. Philadelphia, 7:61, October 20, 1854.—Mexico City, Distrito Federal, México.

La Palma; 8 km. NW of Maravatio (10); Sahuayo; Tupátaro (7).

This species probably is more abundant and widespread than is indicated by the few specimens listed above. It has been found only in the vicinity of permanent water on the Mexican Plateau and the mountains rising from the plateau at elevations of 1500 to 2000 meters. Its apparent absence from Lago de Pátzcuaro cannot be explained, unless Rana dunni replaces it there.

Rana pipiens Schreber

Rana pipiens Schreber, Der Naturforscher, Halle, 18:185, 1782.—Raccoon, Gloucester County, New Jersey.

Aguililla (2); Apatzingán (13); Arteaga; Axolotl (16); Camachines (2); Capirio; Cascada Tzararacua (3); Cerro San Andrés (6); Charapendo (4); Ciudad Hidalgo; Coalcomán (17); Cuitzeo (3); El Sabino (10); Jacona (3); 29 km. NW of Jacona (8); Jiquilpan; La Orilla (3); La Palma (5); La Playa (4); Lago de Chapala (3); Lago de Pátzcuaro (6); Lombardia; Los Conejos (67); Los Reyes (7); Macho de Agua; Maravatio; Morelia (5); Opopeo (3); Pátzcuaro (9); 26 km. S of Pátzcuaro (52); Puerto Hondo (3); Río Duero, 14 km. E of Zamora (13); Río Tepalcatepec, 27 km. S of Apatzingán (2); San Gregorio (38); San José de la Cumbre (5); Tangamandapio; Zacapu; 18 km. W of Zamora (35).

Except on the Pacific lowlands, this species is abundant throughout the state. It has been collected from sea level to 2800 meters, the greatest altitudinal range of any amphibian in Michoacán. It has been found frequently in the Tepalcatepec Valley; it is not a distinctly highland species in southern Michoacán, as stated by Peters (1954:9). One specimen from Aguililla (UMMZ 119257) is an albino. In this specimen there is a faint pattern on the hind limbs; otherwise the entire body is creamy white; the eyes are pink.

Rana pustulosa Boulenger

Rana pustulosa Boulenger, Ann. Mag. Nat. Hist., ser. 5, 11:343, 1883.—Ventanas, Durango, México.

Arteaga (4); 21 km. S of Arteaga; Cascada Tzararacua (3); Coalcomán (3); 12 km. ENE of Dos Aguas (3); El Sabino (53); Los Reyes (3); Tzitzio (4); Uruapan.

Although Rana pustulosa seems to be absent from the Mexican Plateau in Michoacán, it has been collected at elevations of 850 to 2150 meters on the slopes of the Cordillera Volcánico and in the Sierra de Coalcomán. Usually the frogs are found along rocky streams, but at Coalcomán they were found in a hyacinth-choked old river channel, and at El Sabino, in irrigation ditches.

In most specimens the dorsum is dark olive-brown; in some it is pale olive-tan with dense dark brown mottling on the back and dark transverse bands on the hind limbs.

Thirteen tadpoles (UMMZ 94271) taken from a seepage pool by a stream near Uruapan closely resemble the description of tadpoles of this species given by Taylor (1942b).