Bulletin American Museum of Natural History. [Vol. XII, 



clothed, black for the greater part of its length and pure white 

 for the terminal two-fifths. The ears are very small, tufted with 

 long hairs on the inner surface ; hind feet very short and broad. 

 The skull is short and broad, the zygoma heavy and broad but 

 not arched laterally, and the supraorbital edges of the skull are 

 greatly developed, with straight external borders, the interorbital 

 region being thus very broad with nearly parallel edges. The 

 facial portion of the skull is extremely short, the distance between 

 the incisors and the molar series being a little less than the length 

 of the crown surface of the upper toothrow. The teeth are much 

 worn, but indicate a tooth pattern closely like that figured by 

 Giinther for his Lasiuromys villosus (Deville), with which the 

 general character of the skull agrees (cf. P. Z. S., 1876, 744, fig. 

 5). Isothrix rufodorsalis, however, appears on the whole to be 

 very distinct from any of the other described members of the 

 Isothrix group. 



Echimys mincae, sp. nov. 



Type, No. 15389, $ ad., Minca, Santa Marta District, Colombia, July 19, 

 1899 ; Coll. H. H. Smith. 



General color above strong golden brown, lined with black, the pelage of 

 the dorsal area consisting of yellowish brown hairs abundantly intermixed with 

 grooved, black-tipped spines, which appear at the surface as blackish points ; 

 sides lighter and less varied with black, the yellowish brown hairs composing 

 most of the pelage, with a few black-tipped bristly hairs intermixed ; beneath, 

 pure white, including inside of limbs, the pelage rather soft and wholly with- 

 out spines ; sides of the head lighter and more grayish than the sides of the 

 body ; top of head darker than the back, being more mixed with blackish ; 

 outer surface of the fore limbs gray tinged with yellowish, becoming whitish 

 on the upper surface of the feet ; hind limbs externally like the sides of the 

 body, but upper surface of the feet whitish, varying from grayish white to 

 neatly pure white ; ears of medium size, oval, rounded at top, and covered ex- 

 ternally with very fine short hairs, more sparsely clothed within ; tail sharply 

 bicolor, blackish above, nearly white below, clothed for an inch at the base 

 with soft hairs like those of the adjoining parts of the body, the rest of the tail 

 sparsely covered with very short hairs, imperfectly concealing the annulations. 



Young in first pelage, uniform blackish brown above, pure white below. The 

 pelage of the median area of the back is stiff and bristly, the spines in part 

 grooved, but thinner and weaker than in the adult pelage. 



Measurements. Type, total length, 456 mm.; tail vertebne, 210 ; hind foot, 

 \vithout claws, 50, with claws, 57. Twenty adult males and 14 adult females 

 measure as follows : 20 males, total length, 437 (400-490) ; tail vertebrae, 202 

 (186-224) ; hind foot (with claws), 51 (46-57) : 14 females, total length, 413 

 (380-440) ; tail vertebrae, 194. (170-210) ; hind foot (with claws), 46 (42-50). 



