In the following accounts, localities of occurrence in each state are listed from north to south; if two lie in the same latitude, the westernmost is listed first. Localities that are italicized are not shown on the distribution map (Fig. 2), either because undue crowding of symbols would result or, in several cases, because we could not precisely place the localities. Length of forearm is the average of both forearms in individuals in which both forearms could be measured. Lasiurus intermedius intermedius (H. Allen) 1862. _Lasiurus intermedius_ H. Allen, Proc. Acad. Nat. Sci. Philadelphia, 14:246, "April" (between May 27 and August 1), type from Matamoros, Tamaulipas. _Geographic distribution._--Southern Mexico (Yucatan, Chiapas and Oaxaca), northward along Gulf Coast to Rio Grande Valley of southern Texas (see Fig. 2). _Diagnosis._--Size medium (see measurements); sagittal crest present (height above braincase averaging 0.4 mm. in 12 from Brownsville, Texas); interorbital region relatively broad; M3 relatively broad (see comparisons in account of the Cuban subspecies beyond); mesostyle of M1 and M2 and 2nd commissure and cingulum of M3 large; pelage yellowish to yellowish-orange. _Comparisons._--See p. 79 and under accounts of _Lasiurus intermedius floridanus_ and the Cuban subspecies. _External measurements._--Three adult males from the Sierra de Tamaulipas in Tamaulipas: Total length, 146, 136, 142; length of tail-vertebrae, 69, 67, 70; length of hind foot, 11, 11, 11; length of ear from notch, 17, 16, 17; length of forearm (dry), 53.2, 51.8, 51.9. Corresponding measurements for two adult females from 1 mi. SW Catemaco, Veracruz: 149, 155; 64, 69; 11, 12; 17, 17; 51.8, 55.2. Weight in grams of the Tamaulipan specimens, respectively: 24, 21, 24. For cranial measurements see Table 1. _Records of occurrence._--Specimens examined, 45, as follows: TEXAS: 5-5/8 mi. N Mission, 2 (Texas A & M); _Santa Ana National Wildlife Refuge_, 1 (USNM); Brownsville, 13 (4 AMNH; 1 Texas A & M; 8 USNM). TAMAULIPAS: _Matamoros_, 2 (USNM); Sierra de Tamaulipas, 1200 ft., 10 mi. W, 2 mi. S Piedra, 1 (KU); _Sierra de Tamaulipas, 1400 ft, 16 mi. W, 3 mi. S Piedra_, 2 (KU). VERACRUZ: 16 mi. SW Catemaco, 15 (KU). OAXACA: Oaxaca, 1 (British Mus.). CHIAPAS: San Bartolome, 1 (USNM). YUCATAN: Tekom, 1 (Chicago Mus.); Izamal, 5 (USNM). HONDURAS: Rio Yeguare, between Tegucigalpa and Danli, 1 (MCZ). Additional records: TEXAS: _Padre Island_ (Miller, 1897:118); _Cameron County_ (_ibid._). OAXACA: Tehuantepec (Handley, 1960:478). YUCATAN: _Yaxcach_ (not found, Gaumer, 1917:274). Lasiurus intermedius floridanus (Miller) 1902. _Dasypterus floridanus_ Miller, Proc. Acad. Nat. Sci. Philadelphia, 54:392, September 12, type from Lake Kissimmee, Oceola Co., Florida.