NO. 36 NEW MAMMALS FROM PANAMA — GOLDMAN 7 



Color. — Upper parts varying from vandyke brown to mars brown 

 of Ridgway, shaded with black along median line of dorsum, and 

 becoming somewhat paler along sides ; face blackish ; outer sides of 

 limbs dark brown ; under parts dull white, the plumbeous basal color 

 of fur showing through ; feet thinly haired, rather dark flesh-colored ; 

 tail brownish above, grayish below. 



Skull. — Similar in general to that of talamanccB, but rostrum more 

 slender ; parietals bounded laterally by temporal ridges, instead of 

 extending across them and encroaching on squamosals as in tala- 

 mancce; frontal region more depressed near posterior ends of nasals. 



Measurements. — Type: Total length, 252 mm. ; tail vertebrae, 127; 

 hind foot, 32. Skull (type) : Greatest length, 31.3 ; condylobasal 

 length, 28.8; zygomatic breadth, 15.4; nasals, 12,2; interorbital 

 breadth, 5.5 ; interparietal, 8.8 x 4 ; incisive foramina, 5 ; length of 

 palatal bridge, 6.2 ; maxillary toothrow, 4.7. 



Remarks. — This rice rat is a dark-colored, long-haired mountain 

 member of the widely ranging laficeps group, which includes a 

 number of forms in northern South America, and reaches northward 

 as a group, through Middle America to Mexico. Orysomys bom- 

 bycinus is remarkable for the length and softness of its pelage. 



Specimens examined. — Total number, 4, from localities in Panama, 

 as follows: Cerro Azul (type locality), 3; Cerro Brujo, i. 



ORYZOMYS GATUNENSIS, sp. nov. 



Type from Gatun, Canal Zone, Panama. No. 171034. male young, 

 U. S. National Museum (Biological Survey Collection), collected by 

 E. A. Goldman, March 7, 191 1. Original number 20967. 



General characters. — Allied to richmondi; color paler; skull de- 

 cidedly broader between orbits, the sides of frontals more project- 

 ing, interparietal smaller. 



Color. — Upper parts between raw umber and tawny olive of 

 Ridgway, mixed with black, the general color becoming brownish 

 on the face and somewhat buffy along flanks; under parts dark 

 pinkish buff, the plumbeous basal color of fur showing through; 

 feet thinly haired, flesh colored ; tail grayish brown above, lighter 

 below. 



Skull. — Similar in general to that of richmondi, but frontal region 

 broader, the lateral margins more developed as supraorbital shelves ; 

 interparietal much less extended antero-posteriorly ; nasals more 



