AMERICAN BATS — ^HANDLEY 149 



Provided that the data from available samples have not been misinter- 

 preted, the two forms in consequence must be considered distinct but 

 partially sympatric species. 



A few specimens — such as KU 44759 from near Hacienda La Mari- 

 posa, Coahuila, which has the coloration, size, large auricle, and shal- 

 low brain case of P. townsendii, but the short tooth row, short tragus, 

 and few interfemoral cross-ribs of P. mexicanus — ^may be hybrids. In 

 view of the probable close relationship between the two species, it is 

 surprising that such specimens appear to be so infrequent. 



Geographic variation in cranial characters in P. mexicanus seems 

 insignificant; even individual variation in these characters is of small 

 magnitude. Geographic and individual variation in color is slight. 

 The average mass effect of the dorsum in the fine series from Las Vigas 

 is smoky, blackish brown, with the hair tips so dark as to be hardly 

 distinguishable from the dark hair bases. The dark extreme appears 

 almost black to the casual glance, while the pale extreme is brownish, 

 with sooty tones less pronounced, and with the hair tips sUghtly paler 

 than the hair bases. Specimens from the northwestern extremity of 

 the range of the species are somewhat paler than those from the south- 

 east; dark extremes are similar in the two regions. 



The fur is usually rather short and woolly, but specimens from 

 10,500 feet in Estado de Mexico (TCWC 2823), 8,200 feet in Zaca- 

 tecas (USNM 91931), and west-central Chihuahua (USNM 265660) 

 have long, lax fur. This does not appear to be a seasonal phenomenon, 

 for short-haired individuals have been taken in January, February, 

 August, November, and December. The long-haired specimens were 

 taken in February, July, and December. These differences in pelage 

 are not obviously related to age or sex. 



Habitat: Apparently this species is partial to forested mountainous 

 regions, where it roosts in caves, mine tunnels, and buildings. 

 Warmer, less humid, and more desert-like districts in the same general 

 area are inhabited by P. tovmsendii. P. mexicanus has been reported 

 in the following habitats : 



Summer: Flying about rain pool in opening in pine-fir forest on Monte Rfo 

 Frfo (Davis, 1944, p. 380); in ranch house on lower border of oak forest (5,500 

 feet) above Jico (E. W. Nelson, field notes) ; hanging from roof of smaU, damp, 

 north-facing grotto in vicinity of mixed forest of pine, oak, and madrono near 

 Pdtzcuaro (E. W. Nelson, field notes; Goldman, 1951, p. 195). 



Winter: In old mine near Santa Rosa, near summit of Sierra de Guanajuato, 

 upper slopes of which are characterized by light rainfall and second-growth forest 

 of oak, alder, madrono, Crataegus, and wild cherry (E. A. Goldman, field notes; 

 Goldman, 1951, p. 146). Hibernating at 8,200 feet in Sierra de Valparaiso in 

 cold, damp cavern through which strong currents of air passed from one entrance 

 to another; upper slopes of sierra forested with pine, juniper, cypress, oak, mad- 

 rono, and manzanita, frequently interrupted by wet, grassy meadows (E. A. Gold- 



