Distribution in Tamaulipas.—Southern part of state, north at least to Guemes.
At Rancho Pano Ayuctle, according to the field notes of the collector (Schaldach), the red mastiff bat was common, and found daytime retreats in hollows in cypress trees. Schaldach twice found groups of bats in such hollows. M. a. nigricans is an early forager and most individuals seen were in flight before sunset, usually flying in a more or less straight line at heights of 25 to 60 feet above the ground. The odor of the chest gland was described by Schaldach as "strong" and "geranium-like." A female obtained three miles northeast of Guemes on August 19 carried a single embryo that was 33 mm. in crown-rump length.
Specimens examined average slightly smaller than the type specimen, especially in total length, length of hind foot, length of skull and length of maxillary tooth-row. Davis (1951:219) also noted some of these same differences in a specimen examined by him from two miles south of Ciudad Victoria. The variation in color is great among Tamaulipan specimens. Of the 15 examined, two are Dark Mummy Brown, six are Mummy Brown, six are Sudan Brown, and one is paler than Sudan Brown.
I follow Goodwin (1960:6) in using the specific name ater.
Records of occurrence.—Specimens examined, 15: 3 mi. NE Guemes, 2; Rancho Santa Rosa, 25 km. N, 13 km. W Cd. Victoria, 260 m., 2; Rancho Pano Ayuctle, 6 mi. N Gómez Farías, 300 ft., 1; Rancho Pano Ayuctle, 25 mi. N El Mante and 3 km. W Pan-American Hwy., 2200 ft., 8; 8 km. W, 10 km. N El Encino, 400 ft., 2.
Additional records (Davis, 1951:219): 2 mi. S Cd. Victoria; Altamira.
Ateles geoffroyi velerosus Gray
Spider Monkeys
1866. Ateles vellerosus Gray, Proc. Zool. Soc. London, p. 773 (for 1865), April, type locality "Brasil?"; restricted to Mirador, 2000 ft., about 15 mi. NE Huatusco, Veracruz, by Kellogg and Goldman, Proc. U. S. Nat. Mus., 96:33, November 2, 1944.
1944. Ateles geoffroyi vellerosus, Kellogg and Goldman, Proc. U. S. Nat. Mus., 96:32, November 2.
Distribution in Tamaulipas.—Probably extreme southern part.