"284 CALIFORNIA ACADEMY OF SCIENCES. 



Caudal fin obliquely truncate, the upper rays longest, 

 about 4 in the length. 



Anal rounded or truncate in the ? , concavo-convex 

 in the 6 , the longest ray scarcely reaching beyond the 

 middle of the fin. 



Ventral fins short, 1| in the head. 



Pectoral spine about reaching the base of ventral, 

 sometimes a little beyond; 3-3| in the length; soft rays 

 of the pectoral shorter than the spine. 



Dorsal surface light rusty brown; sides and ventral 

 surface plain lighter; humeral region sometimes dotted; 

 upper caudal rays dusky; base of caudal and adipose 

 fins with brown dots; other fins plain, light colored. In 

 the young the tips of the upper caudal rays are rusty. 



Head 4J; depth 5; D. I, 6; A. 23-26; V. 9; P. I, 8-9. 



Fifty-six specimens examined .055-. 13 m. Coary; 

 Hyavary. Agassiz and Bourget. 



226. Auchenipterichthys longimanus. 



Auchenipterus longimanus Giinther, Cat. Fish. Brit. Mus. v, 195, 



1864 (River Capin, Para). 

 Auchenipterichthys longimanus Eigenm. & Eigenm. Proc. Cal. Acad. 



2d Ser. i, 154, 1888 (Maues, Rio Maderia; Cameta). 

 Habitat: Soiithern tributaries of the Amazon. 



Rather stout, little compressed. Head short and 

 broad, its greatest depth 1J in its length, its greatest 

 width 1, width at the rictus 1J ; surface of the bones 

 finely granular, the sutures not conspicuous externally, 

 naked. Dorsal plate broad, a descending process behind. 

 Fontanel open in front. 



Eye 34 in the head, 2| in the interocular distance, 

 longer than the snout. 



Maxillary barbel extending to the middle of the 

 humeral process, mental barbels shorter than the eye, 

 not reaching the origin of the postmentals which reach 

 base of pectorals. 



Gill-openings extending to base of pectorals. Humeral 



