ft'om the Andes of Columbia. 349 



longer than ventral, extending to the middle of the latter. 

 Origin of the dorsal fin just behind the ventrals. Male with 

 a long anal tube, and the posterior anal rajs agglomerated 

 and stiff. Pale olive-brown above, spotted or marbled with 

 blackish brown. 



Eight specimens, the largest measuring 83 millira. 



Chcetostomus setosus. 

 D. 1/7-8. A. 1/3. P. 1/6. V. 1/5. L. lat. 25. 



Head large, much depressed, as long as broad, its length 

 being one third of the total (without caudal) ; occipital and 

 nuchal regions flat. Eye small, its diameter one third the 

 width of the interorbital space. Margin of the snout granu- 

 lated, with short and fine bristles in the female and long and 

 strong ones in the male ; interopercular spines numerous and 

 strong, setiform, curved at their extremity, the hindermost 

 the largest and measuring half the length of the snout. Scutes 

 spiny, the spines being arranged in lines, not keeled ; no 

 distinct posthumeral ridge. Thorax and belly naked. Dorsal 

 fin a little longer than higli ; the anterior rays measure two 

 thirds the length of the head ; the lengtli of its base is less 

 than its distance from the caudal ; four or five scutes between 

 the two dorsal fins. Caudal fin not forked, lower rays longest. 

 The pectoral spine extends to beyond the base of the ventral, 

 which extends to the anal. Eleven or twelve scutes between 

 anal and caudal. Olive above, indistinctly spotted with 

 darker ; fins yellowish, with round black spots ; lower parts 

 uniform yellowish. 



Total length 120 millim. 



Two specimens, male and female. 



Trichomycterus nigromaculatus. 



D. 8. A. 6. P. 9. V. 5. 



Head as broad as long, six and a half times in the total 

 length. The depth of the body contained eight and a half 

 times in the total length. Eye very small, one fourth the 

 length of the snout, one third the width of the interorbital 

 space. The nasal barbel extends to the occiput, the upper 

 maxillary to the base of the pectoral. Opercular and inter- 

 opercular prickles strong. Upper ray of the pectoral pro- 

 longed into a short filament. Origin of the dorsal fin in the 

 middle of the total length. Anal fin entirely behind the 



