_Distribution in Tamaulipas._--Southern part of state in areas of tropical forest. Most individuals of this species were taken in mist nets. Northwest of El Encino for example, bats were collected from a net placed in "a strategic position across a narrow opening" (Schaldach, fieldnotes) in a cave near the headwaters of the Río Sabinas; along the same river at Rancho Pano Ayuctle some were taken in a net stretched across a little creek (arroyo). In the cave near El Encino the collector (Schaldach) estimated the population of _P. rubiginosus_ at between two and three hundred; at Ojo de Agua this bat was found in the deepest part of a cave in association with _Myotis nigricans_. Two June-taken females from the Sierra de Tamaulipas were lactating, and weighed 17 and 18 grams. The generic name _Pteronotus_ is employed instead of _Chilonycteris_ following Burt and Stirton (1961:24-25). The specific name _rubiginosus_ is used in accordance with de la Torre (1955:696). Tamaulipan specimens are assigned to _P. r. mexicana_ because they do not differ from specimens of that subspecies from Nayarit, except that the coloration of Tamaulipan specimens averages slightly darker in both color phases. Specimens of this subspecies from the Sierra de Tamaulipas, previously recorded by Anderson (1956:349), are the northernmost reported in eastern México. _Records of occurrence._--Specimens examined, 31: Sierra de Tamaulipas, 2 mi. S, 10 mi. W Piedra, 1200 ft., 1; Sierra de Tamaulipas, 3 mi. S, 10 mi. W Piedra, 1400 ft., 3; Rancho Pano Ayuctle, 25 mi. N El Mante, 3 mi. W Pan-American Highway, 300 ft., 3; Ojo de Agua, 20 mi. N El Mante, and 3 km. W Pan-American Highway, 300 ft., 2; 10 km. N, 8 km. W El Encino, 400 ft., 22. Additional records (Goodwin, 1954:4): Aserradero del Paraiso; El Pachón. =Pteronotus davyi fulvus= (Thomas) Davy's Naked-backed Bat 1892. _Chilonycteris davyi fulvus_ Thomas, Ann. Mag. Nat. Hist., ser. 6, 10:410, November, type from Las Peñas, Jalisco. 1912. _Pteronotus davyi fulvus_, Miller, Bull. U. S. Nat. Mus., 79:33, December 31. _Distribution in Tamaulipas._--Known only from the two localities reported in this paper. According to field-notes of Schaldach _et al._, individuals of _P. d. fulvus_ appear when it is almost dark (about 6:30 p. m. in December and January), ordinarily fly about 25 feet above the ground, but occasionally are seen at heights of between 60 and 70 feet (near tops of the largest cypress trees). Most bats flew in a straight line for 10 to 20 yards, then zig-zagged, and repeated the same movements. All specimens examined are in the brown color phase. _Records of occurrence._--Specimens examined, 11: Rancho Santa Rosa, 25 km. N, 13 km. W Cd. Victoria, 260 m., 10; Rancho Pano Ayuctle, 6 mi. N Gómez Farías, 300 ft., 1. =Choeronycteris mexicana= Tschudi Mexican Long-tongued Bat