2IO Bulletin American Museum of Natural History. [Vol. V, 



ventral region, the fur grayish plumbeous beneath the surface. The line of 

 demarcation between the coloration of the dorsal and ventral surfaces very 

 indistinct. Ears oval, evenly rounded above, flesh colored at base, dusky 

 apically, sparsely haired. Limbs externally grayish brown, the feet scaly, so 

 thinly haired as to be nearly naked. Palms and soles scaly, the latter 5-tuber- 

 culate. Tail a little shorter than head and body, blackish, nearly unicolor, heavily 

 furred for the basal half-inch or more, the rest scantily clothed with short bristly 

 hairs, which form a very slight pencil at the tip. 



Measurements, average of six adults (four males and two females) taken 

 before skinning : Total length, 402 (380-433) mm. ; head and body, 206 

 (189-223) ; tail, 196 (175-210) ; hind foot, 46.5 (44-48) ; ear from crown, 18.6 

 (16-20). The females are considerably smaller than the males. 



Young. Above uniform mouse-gray, varying to mouse-brown, over the 

 whole dorsal region ; sides with a wash of buff, very slight in the quarter-grown 

 specimens, becoming stronger as the animal increases in age ; ventral surface 

 clear gray, in older specimens whitish gray. 



Skull similar to that of N. apicalis, 1 especially in regard to the size and form 

 of the interparietal, in which it differs notably from N. squamipes. An adult 

 male skull measures as follows: Total length, 2 47 ; basal length, 38 ; greatest 

 zygomatic breadth, 24 ; mastoid breadth, 16.3 ; least interorbital breadth, 3.6 ; 

 length of nasals, 18.3 ; length of interparietal, 4.3 ; width of same, 8.9 ; distance 

 from incisors to first molar, 11.9 ; 'length of crown surface of upper molar series, 

 6.9 ; length of lower jaw (point of incisors to posterior border of condyle), 26.9 ; 

 height at condyle, 13.5. 



Type, No. ffff , $ ad., Princestown, Trinidad, April 10, 1893, coll. Frank 

 M. Chapman. 



This species is based on a series of 12 specimens, 7 of which 

 are adult and five in various stages of immaturity, the youngest 

 about one-fourth grown. 



The adults vary somewhat in coloration, chiefly in the intensity 

 of the yellowish brown above, the amount of black over the 

 middle of the dorsal region, and in the degree of buffy suffusion 

 below, which varies from a slight tinge to a strong wash. The 

 skulls of course vary in size and proportions with age, but in the 



1 As figured by Peters, Abhandl. Akad. Wissensch. zu Berlin, 1860, p. 148, pi. ii. 



2 In this paper " total length," unless otherwise stated, is the distance from the most pro- 



posterior border of occipital condyles. The length of the lower jaw is taken from the tip of 

 the incisors to the posterior edge of the condyle, unless stated otherwise. In all instances 

 measurements are taken with callipers in a straight line between the extreme points 

 mentioned. 



