NO. 22 MAMMALS FROM PANAMA AND MEXICO GOLDMAN 5 



455) ; 214 (299-223) ; 60 (60-61). Skull (type) : Greatest length, 

 55.3; condylobasal length, 50.7; zygomatic breadth, 22.7; nasals, 

 18.8; interorbital breadth, 18; palatal length, 29.7; maxillary tooth- 

 row, 9.8. 



Remarks. — The common squirrel of the Darien region, Panama, 

 is closely allied to 6\ v. morulus from the Canal Zone, but is dis- 

 tinguished by darker color throughout. S. milleri from the moun- 

 tains of southwestern Colombia has the same general pattern of 

 coloration, but differs in darker, more rusty reddish general color, 

 the darkening due in part to the much narrower subterminal bands 

 of the hairs on the shoulders and flanks. In the Darien form the 

 median dorsal stripe is pure glossy black in some specimens, and 

 usually extends well down over the upper base of the tail. Variation 

 from the usual ochraceous rufous coloration of the under parts is 

 shown in one individual by limited areas of pure white near the arm- 

 pits, on the pectoral and inguinal regions, and a very narrow stripe 

 along the median line of the abdomen ; in another the white is 

 reduced to a few hairs near the armpits and on the sides of the lower 

 part of the abdomen. These white areas may indicate gradation of 

 this subspecies toward the South American forms of the S. varia- 

 bilis group in which the under parts are normally white. Specimens 

 from 800 to 2,500 feet altitude, on Cerro Azul, are somewhat inter- 

 mediate between 6\ v. morulus and the Darien form, the dorsal stripe 

 being somewhat indistinct, but in the rich coloration of the under 

 parts they agree with the latter form. 



These squirrels are generally distributed throughout the region 

 visited, ranging upward in the forest from sea level in the Tuyra 

 Valley to over 5,000 feet altitude on the summits of the Pirri Range. 



Specimens examined. — Total number, 18, from Eastern Panama, 

 as follows: Cana (type locality), 5; Boca de Cupe, 1; Cerro Azul, 

 3 ; Marraganti, 3 ; Mount Pirri, 6. 



ORYZOMYS PIRRENSIS, new species' 



Type from near head of Rio Limon (altitude 4,500 feet), Mount 

 Pirri, Eastern Panama. No. 178993, male adult, U. S. National 

 Museum (Biological Survey Collection), collected by E. A. Gold- 

 man, April 29, 1912. Original number 21662. 



General characters. — A large member of the O. meridensis group, 

 similar in size to O. devius, of Western Panama; color slightly 

 darker; metatarsus dark brown instead of flesh color; under parts 

 without the pure white patches usual in the group ; skull large and 



