MARCH, 1904. NK\V SPKCIES OF MAMMALS ELLIOT. 269 



width, 23.5; palatal length, 56; palatal arch to tip of pterygoid 

 process, 20; anterior width of pterygoid fossa, 9; posterior width 

 of basioccipital, 13; length of nasals, 40; length of upper tooth 

 row from anterior edge of canine to posterior edge of last 

 molar, 51 ; of lower tooth row, 57 ; length of mandible, 88. 



This is a very pale form of U. c. calif ornicus , with some of 

 the rich ochraceous coloring of that race, and only tinged 

 with buff in certain places as mentioned above. There are 

 two specimens collected by Mr. Heller, the type with only a 

 restricted amount of black on the back, and the other, younger, 

 without any at all. The tail is very pale, quite different in 

 color from that of U. c. calif ornicus. The skull differs from all 

 those before me of the race just named, in the greater separation 

 of the temporal ridges, the width between them being retained 

 nearly to their posterior junction, and not graduating posteriorly 

 as in U. c. californicus. The pterygoid fossa is shorter and 

 broader, and the basioccipital wider posteriorly. 



FAM. VESPERTILIONID^:. 



PIPISTRELLUS. 

 Pipistrellus hesperus *apus, Subsp. nov. 



Type locality. .Providentia Mines, State of Sonora, Mexico. 



Genl. Char. About the size of P. hesperus, but quite different 

 in color, and with a larger foot. Larger than P. h. australis, the 

 exact color of which is not known. 



Color. Upper parts wood brown, base of fur blackish; under 

 parts pinkish brown; nose, space before and around eyes, wing 

 and tail, membranes, feet and ears black. 



Measurements. Total length, 72; tail vertebras, 31.7; foot, 

 6.3 ; forearm, 30.5 ; thumb, 4; longest finger, 47 ; ear from meatus, 

 10. Skull: occipito-nasal length, 10.5; zygomatic width, 8; 

 interorbital constriction, 3; width of braincase, 6.5; palatal 

 length, 5; post-palatal length, to anterior rim of forearm mag- 

 num, 4; length of upper tooth row, premolars and molars, 3; 

 length of mandible, 8.5; length of lower tooth row, premolar and 

 molars, 3. 



This apparently distinct race of Pipistrellus hesperus was pro- 

 cured by Mr. J. Rowley in the locality given above in the north- 

 ern part of the State of Sonora. Four specimens were procured, 

 and all are much darker, and of a different color from that of P. hes- 



* ar.'j- swift. 



