MAMMALIA COLLECTED IN PERU BY HELLER— THOMAS. 247 



color above, exactly as in Orolestes inca, washed with grayish white 

 below, instead of brown ; and, finally, that it is distinguished from 

 both the other members of the family by the anteorbital vacuities 

 being filled in with bone. In the young specimen, the type, there is 

 still a narrow unossified cleft between the outer corners of the nasals 

 and the maxillae, but in the adult specimen even this is almost com- 

 pletely closed up. 



The very great sexual difference in size between our two adult speci- 

 specitnens of 0. ohscurus is noteworthy (male skull 36.3, female 32.5), 

 this being considerably greater than in Orolestes, but whether it is 

 constant I do not know, nor have I material to state what is the cor- 

 responding difference in C. fuUginosus 



In accordance with the latest conclusions of the paleontologists 

 who have written on the subject, I am now quite prepared to admit 

 that Coenolestes and its allies should be reckoned as more related 

 to the Polyprotodonts than to the Diprotodonts. 



60. DIDELPHIS MARSUPIALIS ETENSIS Allen. 



A young male from Santa Ana, 3,000 feet (No. 194373). 



61. DIDELPHIS PARAGUAYENSIS PERNIGRA Allen. 



Seven specimens as follows : 



Chospyoc, 10,000 feet, 2 (Nos. 194358-9). 



Torontoy, 2 (Nos. 194360-1). 



Machu Picchu, 3 (Nos. 194367-8, 194370). 



While most of the specimens hitherto obtained in southern and 

 southeastern Peru have been in the black phase, these specimens, 

 curiously enough, are with one exception in the gray phase, with the 

 dorsal piles white. They thus exactly resemble average specimens 

 of D. p. andina, the opossum of Ecuador and North Peru. 



62. METACHIRUS NUDICAUDATUS TSCHUDII Allen. 



Adult female, Rio Cosireni, 3,000 feet (No. 194376). 



63. PHILANDER LANIGER ORNATUS Tschudi. 



Adult female, Rio Comberciato, 2,000 feet (No. 194375). 



With well-marked postauricular gray lines, these, like the median 

 patch on the foreback, appearing to be individually variable. Of 

 three specimens from the Upper Maranon, one has them and two 

 have not. 



[MARMOSA RAPPOSA Thomas.] 



[A female and four young in the British Museum from Vilcanota 

 River, Cuzco. Nos. 98.11.16.13-17, the adult the type. O. Garlepp.] 



