6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 56 



ORYZOMYS FRONTALIS, sp. nov. 



Type from Corozal, Canal Zone, Panama. No. 171531, female 

 adult, U. S. National Museum (Biological Survey Collection), col- 

 lected by E. A. Goldman, June 20, 191 1. Original number 21 172. 



General characters. — Similar to 0. flavicans, but decidedly larger; 

 color darker; supraorbital ridges projecting farther over orbits. 



Color. — Upper parts between cinnamon-rufous and orange-rufous, 

 darkened on head by more abundant admixed dusky hairs, becoming 

 paler and duller along sides ; under parts, including lips and inner 

 sides of limbs white ; ears and fore feet brownish ; hind feet dull 

 white; tail dusky all round. 



Skull. — In general form closely resembling that of flavicans, but 

 much larger ; supraorbital ridges more developed, the edges less 

 upturned and shelving farther over orbits. 



Measurements. — Type : Total length, 309 mm. ; tail vertebrae, 161 ; 

 hind foot, 30. Skull (type) : Greatest length, 35.5 ; condylobasal 

 length, 33; zygomatic breadth, 18; nasals, 12; interorbital breadth, 

 6. 7 ; interparietal, 10.2 x 5 ; incisive foramina, 6 ; length of palatal 

 bridge, 6.y; maxillary toothrow, 5. 



Remarks. — The type and only specimen obtained of this large 

 species shows that the animal is clearly a member of the flavicans 

 group. It may be not very unlike O. tectus Thomas, of Bogava, 

 Chiriqui, which is said to have remarkably expanded supraorbital 

 ridges, but the latter is described as having fulvous upper lips and 

 buffy under parts and feet. The species requires no close comparison 

 with O. Havicans illectus which is more orange buffy in color, and 

 has a different skull— the zygomata much less squarely spreading 

 anteriorly, and supraorbital ridges less developed. O. panamensis 

 was described from very near the same locality, but was placed in 

 the laticeps group. 



ORYZOMYS BOMBYCINUS, sp. nov. 



Type from Cerro Azul (altitude 2500 feet), near the headwaters 

 of the Chagres River, Panama. No. 171 105, male adult, U. 

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

 E. A. Goldman, March 26, 191 1. Original number 21009. 



General characters. — Similar in color to carrikeri, but pelage much 

 longer, and skull more slender. Somewhat like talamancce, but color 

 much darker, and pelage longer and softer ; skull with more slender 

 rostrum, and differing in other details. 



