42 Bulletin American Museum of Natural History. [Vol. XIV, 



with the type and other specimens already described (this Bulle- 

 tin, XIII, pp. 191 and 219). The small size of this species, for 

 a member of the genus Didelphis, its intensely black pelage, 

 wholly white ears, and prominent black eye-stripe serve at once 

 to distinguish D. pernigra from any of its congeners. 



2. Thylamys keaysi Allen. Two specimens, $ and ? adult, 

 Inca Mines, May 31 and July 2. 



3. Lagidium peruanum Meyen. One specimen, ? adult, 

 Tirapata, Oct. 18, 1900. Mammae 2, pectoral. Since sending 

 his former field notes on this species (/. <:., p. 220), Mr. Keays 

 has found it to inhabit " a part of the east slope of the Andes, 

 where he found them quite common from 12,000 feet to 16,000 

 feet altitude." The female here recorded, he says, " contained 

 one young ; her teats, two in number, were large and situated on 

 the upper breast." 



4. Dactylomys peruanus Allen. One specimen, male, Inca 

 Mines, June 3, 1900. Although apparently fully adult, the last 

 molar being fully grown and already somewhat worn, it is smaller 

 than the female type (/. c., p. 220). 



This specimen is throughout a little brighter and richer colored 

 than the type, and is doubtless in fresher pelage. The collector's 

 measurements are as follows : Total length, 483 mm. as against 

 560 in the female; head and body, 228 (?, 240) ; tail, 255 

 ( $ , 320) ; hind foot, 44 ( ? , 51). These measurements confirm 

 the small size ascribed to this species in comparison with its 

 congeners. 



5. Proechimys simonsi Thomas. The five additional speci- 

 mens include 3 adult males, i adult female, and i half-grown fe- 

 male, all from Inca Mines. The young example is white below, 

 like the adults, but uniform blackish above, with coarse sub-spiny 

 hairs over the middle of the back. The adults are very uniform 

 in coloration, with the median dorsal area distinctly blackish. 



6. Nectomys garleppii Thomas. Represented by a single 

 half-grown female, dusky brown above with an olivaceous tinge, 

 passing to yellowish olivaceous on the sides. Below buffy, as in 

 the adults, but the buff is of a more olivaceous shade. 



7. Neacomys spinosus (Thomas}. This interesting species 

 is represented by 18 additional specimens, all adult, and all from 

 Inca Mines. They vary greatly in color, in some specimens black 



