APRIL, 1914. MAMMALS OF NORTHERN PERU OSGOOD 147 



theless, a rough hilly country separates Moydbamba from Balsapuerto. 

 The climate is warm but not typically tropical and the nights are always 

 delightfully cool. Work here was done chiefly about the flats along 

 the river and in some rather heavy moist forest near the thermal springs 

 a few miles west of the town. Altitude 2,800 ft. 



Balsapuerto, Aug. 19. The hills and mountains are definitely left 

 behind at Balsapuerto. Within a few miles to the westward is moun- 

 tainous country and distant outlying hills may be seen elsewhere, but 

 in general the region is a flat forested plain. Altitude 700 ft. 



Yurimaguas, Aug. 2^-Oct. 5. Yurimaguas, situated on the Huallaga 

 River at the mouth of the Paranapura, is well within the Amazonian 

 plain wholly surrounded by unbroken forest. Mr. Anderson collected 

 at three localities within a few miles of the town: Munichis, a small 

 Indian village several miles west; Yane Yaku, a chacra or farm on the 

 Paranapura River about 8 miles from Yurimaguas; and Puerto Arturo, 

 a small place a few miles below Yurimaguas on the Huallaga River. 

 Altitude 600 ft. 



Lagunas, Oct. 10-20. A small village on the east bank of the 

 Huallaga River not far above the junction of the Marafion and the 

 Huallaga. It is in the heavily forested rubber district. Collections 

 from this locality were made only by Mr. Anderson. Altitude 500 ft. 



Nazareth, Sept. 10. A village at the edge of a rubber forest on the 

 Yavari River some 20 miles above its mouth and opposite the Brazilian 

 village of Remate de Males. 



Peramys peruvianus Osgood. PERUVIAN PERAMYS. 



Two specimens, Moyobamba. 



These were caught in mouse traps in relatively open forest where 

 the undergrowth was limited. Unfortunately, both were attacked and 

 badly mutilated by ants while in the traps. The skin of the type, 

 however, lacks only part of the tail, ears, and feet and therefore suffi- 

 ciently shows the coloration. The other specimen was preserved in 

 alcohol. This is one of the smaller species of Peramys and appears 

 very distinct from any previously described. 



Didelphis marsupialis Linnaeus. LINN^AN OPOSSUM. 



Two specimens: Moyobamba (i), Yurimaguas (i). 



One of these is in the light and the other in the dark phase and both 

 agree in color with corresponding specimens from northeastern Brazil 

 representing typical D. marsupialis. The skull of the larger specimen, 



