AMERICAN BATS — ^HANDLE Y 151 



Specimens examined: A total of 104 from the following localities 

 in Mexico: 



Chihuahua: Near Pacheco [Sierra de Brena, 8,000 feet], 14s (USNM); Moja- 

 rachic [=Mafuarachic?], Rayon District, Is (USNM). Guanajuato: Santa Rosa 

 [0,500 feet], 13a (USNM). Mexico: Monte Rfo Frfo, 10,500 feet, 28 miles east- 

 southeast of Ciudad M6xico, Is (TCWC). MichoacXn: 2 miles north of Pdtz- 

 cuaro, 7,100 feet, la (USNM). Mokelos: No exact locality, la (USNM). 

 NuEvo Le6n: 22 miles south-southeast of Monterrey, 4as (MCZ). Sonora: 

 Santa Maria Mine, El Tigre Mts., la (UMMZ). Veracruz: Jico [5,500 feet], 

 la (USNM); 2.5 miles east of Las Vigas, 8,500 feet, 59bs (KU), 4s (GF); 6 miles 

 west-southwest of Zacualpilla, 6,500 feet, 3s (KU). Zacatecas: Sierra de Val- 

 paraiso [13 miles west of Valparaiso, 8,200 feet]. Is (USNM). 



Additional records: The following records from Mexico probably 

 refer to this form: 



Puebla: Hacienda de Miguel Sesma, 2 miles northwest of Esperanza (Schwartz, 

 1954, in litt.). Sonora: Sdric (Burt, 1938, p. 26). 



Plecotus rafinesquii Lesson 



Synonymy is given under the subspecies. 



Distribution: Southeastern United States (fig. 19). 



Description: Adult coloration: Hairs of upperparts blackish at 

 base and yellowish brown to reddish brown distally, the two areas 

 sharply demarked ; hairs at posterior bases of ears usually not different 

 from those of remainder of dorsum. Mass effect darkens with wear. 

 Hairs of chest and belly black or blackish at base, white or whitish at 

 tip, the division between the two colors sharp; hairs of chin and throat 

 like remainder of underparts or with buffy wash encroaching from sides 

 of neck; hairs bordering membranes whitish throughout. Immature 

 like adult, except much darker throughout, the Avellaneous tips of 

 the dorsal hairs and the whitish tips of the ventral hairs failing to 

 conceal the blackish hair bases. 



Size medium for the subgenus; presternum with all lobes, but espe- 

 cially the ventral lobe (almost as wide at tip as lateral lobe), somewhat 

 expanded. Rostrum weak and much depressed, rendering facial profile 

 relatively straight; anterior nares relatively small, and posterior border 

 with somewhat angular shape; intermaxillary notch of palate relatively 

 narrow posteriorly; median postpalatal process triangular in shape, 

 v/ith broad base; brain case averages relatively deep for subgenus. 

 I^ with prominent secondary cusp ; P^ normally has small anterointernal 

 cingular cusp. 



Comparisons: Plecotus rafinesquii may be distinguished from geo- 

 graphically contiguous races of Plecotus townsendii by numerous char- 

 acters. When all populations of P. toumsendii are considered, however, 

 the separation is not so striking. Apparently, only coloration will 

 distinguish all the individuals of the two species, all populations 

 considered. P. rafinesquii always has the bases of the ventral hairs 



