160 BULLETIN 144, UNITED STATES NATIONAL MUSEUM 



similar but paler, becoming dull whitish at the anal region. The 

 hair about the eyes and upper lips is blackish brown; ears and 

 membranes the same. Bases of the hairs above and below " plum- 

 beous black." In the lighter phase, the upper surface is a lively 

 " Sudan brown," paling to dull " ochraceous buff " below. Two 

 immature specimens from Patzcuaro are very much darker than the 

 adults, sooty above with the tips of the longer hairs on the back 

 reddish; lighter below, clouded with brownish. In this pelage they 

 are very similar to adults of the northern form of Myotis nigricans, 

 but are distinguishable by the more conspicuous dark underfur on 

 back, smaller foot, and large teeth. 



Skull. — In general form, the skull is quite like that of true Myotis 

 calif omicits, with delicate rostrum, brain case high, oval, tapering at 

 the front end and not flat topped like that of M. subulatus and its 

 races. In the Patzcuaro series, it is very distinctly larger than in 

 tnie coHifoTnicus, or indeed than in the specimens from Oaxaca. 



Measurements. — For measurements see tables, pages 162 and 164. 



Specimens exannined. — Total number 78, from the following 

 ^calities : 



GUANAJUATO: Guanajuato, 1 ale. (A. N. S. P.). 



JALISCO: Los Masos, 6 skins (A. M. N. H.) ; Santa Rosalia, 1 ale. (B. M.) ; 



Sierra Nevada de Colima, 9 skins (A. M. N. H.). 

 MICHOACAN: Patzeuaro, 8 skins, 41 ale. (U.S.N.M.). 

 OAXACA: Reyes, 5 skins (U.S.N.M.) ; Cuicatlan, 1 ale. (U.S.N.M.). 

 SAN LUIS POTOSI: La Parada (Hda.), 1 ale. (U.S.N.M.). 

 TAMAULIPAS: Miquihuana, 2 ale. (U.S.N.M.). 

 TRES MARIAS ISLANDS: 1 ale. (B. M.). 

 VERA CRUZ: Mirador, 1 ale., type of agilis (A. N. S. P.). 

 ZACATECAS: San Juan Capistrano (Hda.), 1 ale. (U.S.N.M.). 



Remarks — Saussure's description of a small Myotis occurring in 

 the hot part of the Province of Mexico, and having a forearm of 

 33 mm. in length, is taken to refer to the representative of Myotis 

 calif amicus here described. The color of the type, after immersion 

 in alcohol, was said to be golden brown, grayish below. This ex- 

 cludes the possibility that Saussure had in hand a form of M. 

 nigricans. 



The series from Patzcuaro, Michoacan, seems typically large and 

 dark. Of similar large size is the type specimen of VespertiUo agilis 

 H. Allen, from Mirador, Vera Cruz ; hence this name is undoubtedly 

 a synonym of mexicanu^. A series of skins from Reyes, Oaxaca, is 

 slightly but distinctly smaller, and the skulls average a little less in 

 size. 



