NORTHWESTERN SOUTH AMERICA. 



677 



4. Astroblepus grixalvii micrescens var. nov. 



The following specimens came from the western slope of the 

 eastern Andes, north of Bogota. They were collected by Manuel 

 Gonzales. 



Specimens Examined. 



This variety greatly resembles A. unifasciatus and A. orientalis; 

 it differs from the former in the nature of the adipose fin, and from 

 the latter at least in the length of the pectorals and ventrals. 



Head 3.75-4; D. I, 6; A. 7; interocular 4-4.5 in the head, 

 slightly less than the distance between posterior nares and eye ; 

 nasal flap broad, its outer angle slightly produced or not ; barbel 

 about reaching the gill-opening, sometimes falling a little short and 

 sometimes extending a little beyond ; pectorals broad, the divided rays 

 fan-shaped, extending about to the ventrals, the outer ray reaching 

 almost to the second third of the ventrals ; ventrals lanceolate, their 

 origin under the first dorsal ray ; the outer ray reaching nearly to or 

 beyond the anus, which is two thirds to three fourths the distance 

 from the origin of the ventrals to the anal ; anal obliquely truncate, 

 the anterior ray always extending beyond the following one in the 

 female ; the first and second membranes in the male very w'ide, the 

 third, fourth and fifth rays close together and extending beyond the 

 first two and the last two, not near reaching the caudal ; caudal 

 symmetrically emarginate, the outer rays prolonged ; adipose fin in 

 the young an adnate or subadnate spiniferous spine, with age a 

 dermal ridge develops in which the spine disappears or is retained 

 as a non-spiniferous stay. (The process does not take place at the 



