192 CALIFORNIA ACADEMY OF SCIENCES. 



Upper jaw slightly the longer. Teeth all firmly set, 

 those of the jaws in bands of equal depth. Vomerine 

 teeth in two patches which become united in the old; 

 palatine teeth remote, in two longitudinally ovate patches. 



Gill-rakers overlapping, 4-f 15. 



Dorsal spine very variable, longer than head in young, 

 J shorter than head in adult. Base of adipose dorsal 

 equals length of head. Caudal deeply forked, the lobes 

 about equal to the head in length. Pectoral spine 

 roughened on its anterior margin, strong hooks on its 

 posterior margin, its length IJ-l-J- in head. 



Dorsal fin with large round dusky spots; barbels 

 annulated with light and dark. 



Head 4; depth 5-5J; D. I, 9 to 10; A. 11. 



140, Sciades marmoratus, 



Sciades marmoratus Gill, Proc. Acad. Nat. Sci. Philad. 1870, 95 

 (Upper Amazons). Eigenm. & Eigenm. Proc. Cal. Acad. 2d. Ser. 

 i, 136, 1888 (Tabatinga). 



Habitat: Maranon. 



The specimens examined by us are from Tabatinga; 

 they measure .50 and .58 m. 



The teeth on the vomer are longitudinally ovate and 

 not as in Dr. Gill's specimen " transversely ovate." 



The vomerine teeth are in two patches, even in the 

 largest specimen. 



Width of head at angle of mouth 1| in greatest width, 

 If in length of head; eyes pointing upward and out- 

 wards; no dermal ossification in adult. Body subterete, 

 heaviest under first dorsal spine. Head flattish, de- 

 pressed. 



Eye small, 4J in snout, 10 in head, 5 in interorbital, 

 \\ diameters behind the rictus. 



Maxillary barbels extending to end of adipose fin; 

 mentals to base of pectoral; postmentals to tips of 

 pectorals. 



Teeth as in the young of longibarbis; the palatine 



