136 Proceedings of the Biological Society of Washington. 



Gila Mountains (near Tinajas Altas ), 3; Granite Mountains (near Tule 

 Wells), 1; Tinajas Altas (type locality), 4; Tule Wells, 2. 



Neotoma albigula sheldoni subsp. nov. 



SHELDON WOOD RAT. 



T)/pe from Pinacate Mountains (Papago Tanks), Sonora, Mexico, No. 

 206,812, U. S. National Museum (Biological Survey Collection), collected 

 by Charles Sheldon , 1915. 



General characters. — A dark colored form of the N. albigula group, 

 differing from N. a. albigula and N. a. mearnsi in the peculiar vinaceous 

 bufliy general tone of the upperparts. 



Color. — Type (fresh pelage): Upperparts in general vinaceous-bufF, 

 purest on shoulders and sides, the back rather strongly darkened by black 

 hairs ; head grayish ; underparts white, the fur pure white to roots on 

 throat, chest, and inguinal region, as usual in N. a. albigula ; ears and 

 orbital borders blackish; feet white; tail sharply bicolor, black above, 

 white below. In one specimen the vinaceous-bufF of sides extends across 

 the abdomen, but the throat and chest are pure white as in the others. 



Skull. — About like that of N. a. albigula. 



Measurements. — Type (dry skin): Total length, 334; tail vertebrte, 

 136; hind foot, 32.5 Skull (type): Greatest length, 44; zygomatic 

 breadtli, 23.1 ; interorbital breadth, 5.5; length of nasals, 16.9; length 

 of anterior palatine foramina, 8.9; length of palatal bridge, 7.4; length 

 of upper molar series, 8.5. 



Remarks. — In the pronounced vinaceous buffy shade of the upperparts 

 and more copious admixture of black, this form contrasts strikingly 

 with its exceedingly pallid relative, N. a. mearnsi, of the region along 

 the international boundary, only 40 or 50 miles away. The two forms 

 agree so closely in cranial details, however, that it seems best to regard 

 them as subspecies. The dark color of the form inhabiting the Pinacate 

 Mountains seems to be associated with that of its lava environment. It 

 is named for the hunter-naturalist, Charles Sheldon, who collected the 

 material which forms the basis of this description, and through whose 

 interest and generosity much has been contributed to our knowledge of 

 many North American mammals. 



Specimens examined. — Ten, all from the Pinacate Mountains. 



Noctilio leporinus mexicanus subsp. nov. 



MEXICAN BULLDOG BAT. 



Type from Papayo, Guerrero, Mexico. No. 126,672, male adult, U. S. 

 National Museum (Biological Survey Collection), collected by E. W. 

 Nelson and E. A. Goldman, April 17, 1903. Original number 16,318. 



General characters. — Closely resembling N. I. leporinus and N. I. 

 mastivus but smaller, the difference in size most noticeable in the skull. 

 Maxillary toothrow short. 



Color. — Male (type) : About as in N. I. leporinus, the general color of 

 upperparts rich, dark, ochraceous-tawny (Ridgway, 1912), becoming 



