290 Mr. O. Thomas on new 



Collected June 1899 and presented by Walter Goodfellow, 

 Esq. A second specimen, labelled as from the Rio Napo, 

 has been in the Museum since 1875. 



Phyllotis amicus and its subspecies. 



After obtaining the specimens of this species — at Eten, 

 Reque, and Tolon — mentioned in the original descrip- 

 tion *, Mr. Simons collected a number further inland and 

 higher up at Uramarca, on the River Ushpe, not far from 

 Pallasca. The three localities (for Eten and Reque may be 

 treated as one) are all approximately at the same latitude ; 

 but the first is on the coast, in the desert region, at an alti- 

 tude of only 20-50 metres, the second, Tolon, about 60 miles 

 inland at 100 metres, and the last is at about 1200 metres on 

 the Andean chain. 



On comparing the three sets it proves that the coast 

 specimens are smaller and paler in colour than the middle, 

 typical, set from Tolon, while, on the other hand, those from 

 Uramarca are larger, with longer tails and, especially, much 

 larger ears. Further south, on the Shigray River, Tambo 

 (1600 metres), and at Marca (2000 metres), the same large 

 long-eared form occurs, while at Chosica, near Lima, at 

 850 m., the local representative of Ph. amicus is again much 

 like that found at Tolon. 



It would therefore seem that along the higher level (1200- 

 2000 m.) from about lat. 7° to 12° S., the long-eared form 

 occurs, that the intermediate typical one ranges along the 

 middle altitudes (100-850 m.), while the Eten one may also 

 hereafter be found to occur further southwards along the 

 coast, perhaps to Callao. 



The subspecies may be briefly distinguished as follows : — 



Phyllotis amicus maritimus, subsp. n. 



Size small (head and body averaging 78*5 millim. in six 

 specimens); tail short (96*6); ears short (22 - 25). 



Colour paler and more sandy than in the typical form, 

 especially posteriorly ; approximating to the darker specimens 

 of the desert species Ph. gerbillus. 



Dimensions of the type (measured by collector in the 

 flesh) :— 



Head and body 80 millim. ; tail 100 ; hind foot 22 ; ear 

 22*5. 



Skull: basilar length 17'1. 



* Ann. & Mag. Nat. Hist. (7) v. p. 355 (1900). 



