SOUTH AMERICAN NEMATOGNATHI. 137 



Distance of dorsal fin from snout 3 in the length; 

 dorsal rays of nearly uniform height, higher than the 

 spine. Distance of the adipose from the dorsal fin 2 in 

 the length of the dorsal fin, its distance from the caudal 

 less than a diameter of the eye. 



Caudal deeply forked, the lower lobe broader, rounded, " 

 1J in head. 



Anal longer than high, its longest ray 2J in head; tip 

 of the anal fin not reaching the vertical from the end of 

 the adipose by the length of the snout. 



Ventrals inserted behind the vertical from last dorsal 

 ray, 2 in head. 



Pectoral spine very strong, scarcely shorter than the 

 longest ray, recurved hooks on upper three-fourths of its 

 outer margin; a deep groove almost the upper half of 

 its inner margin, the basal third roughened; its length 

 If in head. 



Color brownish; fins dusky; adipose margined with 

 black. 



Head 4J; depth 6f; depth, above first anal ray, 8; 

 depth of caudal peduncle 10; Br. 7-8; D. I, 6; A. 11. 



Type No. 7547. Length .31 m. Cudajas. 



XVI. RHAMDELLA. 



Rhamdellaftigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. 

 i, 129, 1888 (eriarcha). 



Type: Rhamdella eriarcha E. & E. 



Fontanel continued to the occipital process, a bridge 

 behind the eyes. Dorsal and pectoral fins with strong 

 spines. Ventrals placed below or behind the dorsal. A 

 free orbital margin. 



Habitat: Rio Janerio to Mexico. 



ANALYSIS OF THE SPECIES OF RHAMDELLA. 



a. A. 15-18. 



b. Adipose fin little longer than anal. 



