Putorius (Arctogale) muricus Bangs, Proc. New England Zoöl. Club, 1:71, July 31, 1899.

Putorius streatori leptus Merriam, Proc. Biol. Soc. Washington, 16:76, May 29, 1903. Type from Silverton, San Juan County, Colorado.

Putorius muricus, Stephens, California Mammals, p. 248, 1906.

Putorius cicognani, Taylor, Univ. California Publ. Zoöl., 7:298, June 24, 1911.

Mustela streatori leptus, Miller, U. S. Nat. Mus. Bull., 79:96, December 31, 1912; Bailey, N. Amer. Fauna, 35:48, September 5, 1913; Dixon, Journ. Mamm., 12:72, February 12, 1931; Whitlow and Hall, Univ. California Publ. Zoöl., 40:246, September 30, 1933.

Mustela muricus, Miller, U. S. Nat. Mus. Bull., 79:96, December 31, 1912; Kellogg, Univ. California Publ. Zoöl., 12:358, January 27, 1916.

Mustela cicognanii lepta, Dice, Journ. Mamm., 1:12, November 28, 1919; Hall, Mamm. Nevada, p. 184, July 1, 1946.

Mustela rixosa, Seton, Journ. Mamm., 14:70, February 14, 1933.

Mustela cicognanii leptus, Miller, Journ. Mamm., 14:368, November 13, 1933; Bailey, N. Amer. Fauna, 55:293, August 29, 1936.

Mustela erminea murica, Hall, Journ. Mamm., 26:84, February 27, 1945; Hall, Journ. Mamm., 26:181, July 19, 1945.

Type.—Male, young, skull and skin; no. 9146, collection of E. A. and O. Bangs in Mus. Comp. Zoöl.; Echo, 7500 ft., El Dorado County, California; July 15, 1897; obtained by W. W. Price and E. M. Nutting.

The skull has a fracture along the sagittal suture and fractures on the left side of the braincase but these have been glued, and no part of the skull is missing except in the region of the right P4 which part has been shot away. On the left side m2 never developed. Excepting this tooth and the right P4, all the teeth are present and entire. The skin is well made but has the soles of the hind feet turned up.

Range.—Near 5300 feet (Denver) to 11000 feet (Santa Fe Baldy); typically boreal but taken in Upper Sonoran Life-zone in winter at Denver; from central and southwestern Montana, southern Idaho, and Blue Mountains of southeastern Washington southward east of the Cascade Divide through the Salmon River Mountains and Sierra Nevada at least into Fresno County of California, in the Great Basin to central Nevada, in the Rocky Mountains into northern New Mexico; eastward to the Black Hills. See figure [25] on page [95].

Characters for ready recognition.—Differs from M. e. invicta by hind foot less than 36 and basilar length less than 35 in males and by hind foot less than 29.5 and basilar length less than 30.5 in females; from M. e. gulosa, in both sexes, by upper parts lighter, tone 2 of Chocolate or lighter (see description of color), least width of light-colored underparts averaging about two-thirds instead of one-third of greatest width of dark-colored upper parts, in males, on the average, tail less than 65, weight of skull less than 0.90 grams, basilar length less than 30.8 grams; from M. e. streatori, in both sexes, by upper lips white (not brown), light color of underparts extending down hind leg below knee, depth of skull at posterior border of upper molars less than 7.7 in females and ordinarily less than 9.6 in males, tail less than 62 in males and less than 49 in females.

Description.—Size.—Male: An adult from Black Butte, California, measures: Total length, 227; length of tail, 55; length of hind foot, 27. Corresponding measurements of another from Wheeler Peak, Nevada, are: 220, 56, 26. Two subadults from Colorado, one from Crested Butte and another from Coventry, measure, respectively, as follows: 238, 227; 66, 60; 30, 30. An adult from Wheeler Peak, Nevada, weighs 57.7 grams and another from 2 mi. W Black Butte, Calif., 54.5 grams.

Female: Two adults from Teton County, Wyoming, measure: Total length, 205, 200; length of tail 52,—; length of hind foot, 23, 23.7. A subadult from 9-1/2 mi. E Pocatello, Idaho, measures: 197, 50, 25. An adult from Wheeler Peak, Nevada, has corresponding measurements of 190, 42, 23, and weighs 33.8 grams.

Color.—As described in Mustela erminea richardsonii except that upper parts tone 2 or lighter of Chocolate of plate 343 of Oberthür and Dauthenay; underparts white, Pale Buff or with faint wash of Sulphur Yellow; least width of color of underparts in male from Black Butte and one from Wheeler Peak, amounting to 65 and 59 per cent of greatest width of color of upper parts. Black tip of tail, respectively, 28 and 33 mm., which amounts to 51 and 59 per cent of length of tail-vertebrae. In two adult females, one from Teton County, Wyoming, and one from Wheeler Peak, Nevada, the least width of the underparts amounts to 55 and 60 per cent of the greatest width of color of upper parts. Black tip of tail, respectively, 23 and 19 mm., which amounts to 44 and 45 per cent of length of tail-vertebrae.

From the other subspecies of small-sized weasels of more northwestern occurrence, namely anguinae, fallenda, olympica, streatori and gulosa, muricus differs in lighter color of upper parts, wider light-colored underparts and relatively longer black tip of tail.

Skull.—Male (illustrated by 5 adults in table of measurements, which see): See plate [7]. As described in Mustela erminea richardsonii except that: Weight, 0.78 (Wheeler Peak) and 0.85 (Black Butte) grams; basilar length, 30.6 (29.8-31.2); length of tooth-rows more or less than (approximately equal to) length of tympanic bulla.

Female (illustrated by 6 adults in table of measurements, which see): See plates [12]-[14]. As described in Mustela erminea richardsonii except that: Weight, 0.60 (0.575-0.645); basilar length, 28.0 (27.3-29.4); breadth of rostrum approximately 30 per cent of basilar length.

In comparison with streatori, males average smaller in every measurement taken with no overlap in most dimensions; 25 per cent lighter; anterior margin of tympanic bulla more nearly flush with squamosal, that is to say less protruded from braincase; in relation to other dimensions of skull, braincase shallower anteriorly (at plane of last molars) and deeper posteriorly (at anterior end of basioccipital). Females average smaller in every measurement taken except mastoid and zygomatic breadths which are actually more; 6 per cent lighter; in relation to other parts of skull, preorbital and interorbital parts slightly smaller; in relation to length of skull, braincase shallower. Comparison with invicta and gulosa is made in the accounts of those subspecies.

Remarks.—The smallest males of the entire species are of this subspecies and the females of it are barely larger than those of olympica and gulosa and hence are among the three smallest. The material now available consists only of one or a few specimens from each of several widely separated localities. If as many specimens per unit area were available as there are of the species M. erminea from southern British Columbia, geographic variation warranting the division of muricus into more than one subspecies might be revealed. Evidence pointing in this direction is comprised in the pale color and small size of the pair of adults from Wheeler Peak on the eastern border of Nevada; the suggestion is that there is a distinct pale race of small individuals in the isolated spots of boreal life-zone in the mountains of the desert. The color and size of the specimens from the Toyabe Mountains, and that from the Pine Forest Mountains, both places also in Nevada, nevertheless, lend no support to this suggestion. Comparison of specimens from the Rocky Mountains of Colorado with those from the Sierra Nevada of California gives no basis for recognizing more than one subspecies. Therefore, Putorius streatori leptus Merriam with type locality at Silverton, San Juan County, Colorado, falls as a synonym of the earlier named Putorius (Arctogale) muricus Bangs with type locality at Echo, El Dorado County, California. Furthermore, specimens from northern New Mexico, the southernmost known area of occurrence for the subspecies (and for the species), are as large as specimens from far north in the range of the subspecies, say, in northwestern Wyoming; there is therefore no evidence of progressive decrease in size to the southward as in advance of study I supposed existed in muricus. This erroneous supposition was held because I knew that there was a decrease in size to the southward in the species as a whole and also in each of the subspecies richardsonii and invicta directly to the north of muricus.

Intergradation with invicta is shown by specimens from southwestern Montana. Where the margins of the geographic ranges of invicta and muricus approach one another elsewhere, low-lying territory, zonally unsuited to the existence of the species, occurs along the Snake and Columbia rivers, and precludes any chance of intergradation except around the head of the Snake River Plains. Two specimens, here referred to muricus, from Siskiyou County, California, in both color and cranial characters, are intergrades with streatori and might be referred with almost equal propriety to streatori.

Specimens examined.—Total number, 52, arranged alphabetically by states, then by counties from north to south within each state. Unless otherwise indicated, specimens are in the Museum of Vertebrate Zoölogy, University of California at Berkeley.

California. Siskiyou County: head of Rush Creek, 6400 ft., 1; Castle Lake, 5434 ft., 1. Tehama County: 2 mi. W Black Butte, 6800 ft., 1. Placer County: ridge W of Tahoe Pines, Lake Tahoe, 1; Blackwood Creek, 6250 ft., near Tahoe Pines, 1. El Dorado County: Fallen Leaf Lake, 6500 ft., 1[33]; Echo, 1[75]. Tuolumne County: Ten Lakes, 9200 ft., Yosemite Park, 1. Mariposa County: Vogelsang Lake, 10350 ft., Yosemite Park, 1. Mono County: Mammoth, 1[59].

Colorado. Rio Blanco County: Marvine, 1. Boulder County: Camp Albion, 10600 ft., 1[60]; Boulder, 1[91]. Denver County: Denver, 1[57]. Park County: Jefferson, 1[57]. Gunnison County: near Placita in Gunnison County, 1[26]; Crested Butte, 9000 ft., 3 (1[91], 2[19]). El Paso County: Turkey Creek, SW Colorado Springs, 6000 ft., 1[19]. Chaffee County: Arbourville, 1[91]; Hancock, 1. Montrose County: Coventry, 6800 ft., 1[19]. San Juan County: Silverton, 1[91]; in San Juan County above timberline, 1[87].

Idaho. Bannock County: West Fork of Rapid Creek, 9-1/2 mi. E Pocatello, 1.

Montana. Meagher County: Camas Creek, Big Belt Mts., 4 mi. S Ft. Logan, 1[91]. Beaverhead County: Donovan, 1[91]. County in question: Yellowstone Park, 1[75].

Nevada. Humboldt County: Alder Creek, 6000 ft., Pine Forest Mts., 1. Ormsby County: 1/2 mi. S Marlette Lake, 8150 ft., 1. Nye County: South Twin River, Toyabe Mts., 1[91]. White Pine County: Baker Creek (8500 ft., 8675 ft., 11100 ft.), 3.

New Mexico. Taos County: Twining, 10700 ft., 1[91]. Sandoval County: 9 mi. E Cuba, 9000 ft., 1. Santa Fe County: Saddle S of Santa Fe Baldy, 11000 ft., Santa Fe Range, 1[1].

Oregon. Wasco County: Mill Creek, 20 mi. W Warmsprings, 1[91]. Klamath County: Fort Klamath, 1[91].

South Dakota. Pennington County: 4 mi. SE Hill City, 5300 ft., 2[76]; Pfander's Ranch, 3 mi. SSE Hill City, 5300 ft., 1[76]; Palmer Gulch, 3 mi. SE Hill City, 5300 ft., 1[76]; Spring Creek, 2 mi. W Oreville, 5500 ft., 1[76]. Custer County: 1/2 mi. E Sylvan Lake, 6250 ft., 1[76].

Washington. Columbia County: Butte Creek, 1; Stayawhile Spring, 5150 ft., 1.

Wyoming. Crook County: 5 mi. NW Sundance, 5900 ft., 1[93]. Teton County: Whetstone Creek, 2[76]; 1/4 mi. E Moran, 6700 ft., 1[93]. Sublette County: 1/2 mi. NE Pinedale, 7500 ft., 1[93]. Albany County: 30 mi. N and 10 mi. E Laramie, 6560 ft., 1[93]; 26 mi. N and 4-1/2 mi. E Laramie, 6960 ft., 1[93]. Carbon County: 8 mi. N and 19-1/2 mi. E Savery, 8800 ft., 2[93].

Mustela erminea? angustidens (Brown)

Plates [7], [12], [13] and [14]

Putorius cicognanii angustidens Brown, Mem. Amer. Mus. Nat. Hist., 9 (pt 4):181, pl. 17, 1908.

Mustela cicognanii angustidens, Hay, Iowa Geol. Surv. Bull., 23:32, 1914; Hay, Carnegie Inst. Washington, Pub. no. 322A:252, October 15, 1924; Hay, ibid., Pub. no. 390 (vol. 2): 528, 1930; Hall, ibid., Pub. no. 473:111, 112, November 20, 1936.

Type.—Female, adult, skull and lower jaws lacking zygomata, right P2 and incisors, no. 12432, Amer. Mus. Nat. Hist.; from Conard Fissure, four miles west of Willcockson, Newton County, Arkansas; obtained sometime in the period 1903 to 1905 inclusive (see plates [8], [14]).

Range.—Known only from the Pleistocene deposit in Conard Fissure, at the type locality in northern Arkansas.

Description.—Skull.—Male (based on nos. 12437, 12441 and 12444): See measurements and plates [7] and [8]; weight, unknown; basilar length, 38.1 (36.6-39.2); length of tooth-rows more than length of tympanic bulla; breadth of rostrum measured across lacrimal processes less than a third of basilar length; interorbital breadth ordinarily equal to distance between glenoid fossa and posterior border of external auditory meatus; zygomatic breadth probably averaging approximately the same as distance between last upper molar and jugular foramen.

Female (based on nos. 11766 and 12435): See measurements and plates 8, 12-14; weight, unknown; basilar length, 34.0 (32.5-35.1); length of tooth-rows more than length of tympanic bulla; breadth of rostrum about equal to (more or less than) 30 per cent of basilar length; interorbital breadth less than distance between glenoid fossa and posterior border of external auditory meatus; zygomatic breadth probably less than distance between last upper molar and jugular foramen.

Comparison of the cranial description given above with those of the American races of erminea from the far north will show that many characters are held in common—more than with more southern subspecies of erminea.