6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 60 



tail brownish and nearly unicolor, clothed with very short incon- 

 spicuous hairs leaving the annulations showing distinctlv. Young 

 (about one-third grown) : Decidedly darker than in flavidus of 

 corresponding age. 



Skull— Larger than that of flavidus, with rostrum less swollen 

 laterally : nasals more attenuate posteriorly ; anterior lobe of first 

 upper molar decidedly, narrower, the longitudinal notch shown in 

 flavidus faint or absent. 



Measurements. — Type: Total length, 348 mm.; tail vertebrae, 

 185; hind foot, 35.5. Average of six adult topotypes : 356 (342- 

 376) ; 197 (185-204) ; 36 (35-36.5). Skull (average of six adults) : 

 Greatest length, 42.3 (40.8-44.2) ; condylobasal length, 38.1 (37-40) ; 

 zygomatic breadth, 20.6 (20.2-21.5) ; nasals, 17.5 (16.5-19.2) ; inter- 

 orbital breadth, 6.1 (5.8-6.5) ; interparietal, 11 x 5.2 (9.8 x 4.8-12. 1 

 x 6) ; incisive foramina, 7.9 (7.3-8.2) ; length of palatal bridge, 7.1 

 (7-7.8) ; maxillary tooth row, 6.1 (5.9-6.3). 



Remarks. — -This species is evidently more closely allied to flavidus 

 than to any other known form, but differs notably in dentition. The 

 anterior lobe of the first upper molar is narrower, less extended 

 internally, and the longitudinal notch is faint or absent. The supple- 

 mentary cusps are rather weakly developed for a Megadontomys. 

 and the general form of the tooth suggests the 5-tuberculate condi- 

 tion of typical Peromyscus. In flavidus, on the contrary, the division 

 of the anterior lobe being more complete the dentition is not very 

 unlike that of the G-tuberculate genus Rhipidomys. 



Specimens examined. — Twenty, all from 3,500 to 5,200 feet alti- 

 tude in the vicinity of Mount Pirri. 



NEACOMYS PICTUS, sp. nov. 



Type from Cana (altitude 1.800 feet), in the mountains of eastern 

 Panama. Xo. 1787 17, male adult, U. S. National Museum (Biologi- 

 cal Survey Collection), collected by E. A. Goldman, March 13, 1912. 

 Original number 21 5 12. 



General characters. — Similar in color to N. pusillus from the coast 

 region of western Colombia, but decidedly larger ; feet white instead 

 of yellowish; pelage of upper parts composed of grooved black- 

 tipped spines and slender orange rufous hairs. 



Color- Upper parts orange rufous mixed with black, resulting 

 in a grizzled effect, the black predominant on head, middle of face, 

 and lower part ^i back; sides, shoulders and cheeks paler, more 

 ochraceous buff, this color clearest along a sharp line of demarca- 



