136 CALIFORNIA ACADEMY OF SCIENCES. 



in the length. Distance of adipose fin from the dorsal 

 equals the length of the dorsal. Adipose fin very low in 

 front, its length about 3J in the length. 



Pectorals and ventrals very short. Pectoral spine 

 short, terete, about half as long as the head, its outer 

 margin smooth, the inner margin with strong teeth the 

 entire length. 



Color brown, the sides and back densely covered with 

 small brown dots and more minute black ones; a dark 

 humeral spot; a narrow, dark lateral band. 



Head 4J: depth above first anal ray 7; depth of the 

 peduncle 9J; Br. 6; D. I, 6; A. 13. 



One specimen .175 m. (to base of caudal). Goyaz. 

 Senhor Honorio. 

 96, Rhamdia tenella, 



Rhamdia tenella Eigeniu. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 127, 

 1888 (Cudajas). 



Width behind the head equal to the depth, tapering 

 to the strongly compressed caudal peduncle. Head 

 broad and flat transversely, its greatest width 1J in its 

 length; profile regularly and strongly convex; width at 

 angle of mouth 2 in length of head. Foiitanel a narrow 

 slit between the frontal bones. Occipital process ex- 

 tending a third of the space from its base to the dorsal 

 spine. 



Eye 3 in snout, 9 in head, 2J in the interorbital. 



Maxillary barbels reaching beyond the dorsal fin, men- 

 tal barbels to base of pectoral, postmentals to middle of 

 pectorals. 



Lower jaw shorter than the upper; 

 intermaxillary band of teeth twice as 

 deep at outer margins as at the mid- 

 dle; the greatest depth of the band 3J 

 in its width. 



Gill-membranes separate to below angle of mouth; 

 gill-rakers slightly branched, 3+10. 



