53. PIMELODUS. 117 



B. Head not grauiilated ; the occipital process reaches the basal boue 

 of the dorsal spine, which is feeble. 



4. Pimelodus cristatus. 

 Pimelodiis cristatus, 3Iidl. (^ Trosch. Hor. Ichth. iii. p. 4. 



D. 1/6. A. 15. P. 1/9. 



Head covered with very thin skin above ; occiiDital process nar- 

 row, elongate, nearly thrice as long as broad, extending on to the 

 small triangular basal bone of the dorsal spine. Adipose fin very 

 long, two-fifths of the total length (without caudal) ; its distance 

 from the dorsal fin is one-half of the length of the latter. The max- 

 illary barbels extend beyond the origin of the adipose fin, the outer 

 ones of the mandible beyond the extremity of the pectorals. 



The height of the body is contained five times and a half in the 

 total length (without caudal) , the length of the head four times and 

 two-thirds ; snout rather narrow, with the upper jaw somewhat 

 longer than the lower ; the band of intermaxillary teeth tapering 

 on the sides, four times as broad as long. The eye is situated some- 

 what behind the middle of the head (its diameter is one-foui'th of 

 the length of the head, and equal to the width of the interorbital 

 space*). Dorsal spine slender, nearly as long as the head, slightly 

 serrated along both edges ; dorsal fin nearly twice as high as long, 

 and much higher than the body t. Pectoral spine serrated along both 

 edges, three-fourths of the length of the head. Caudal fin cleft to 

 the base, with the lower lobe longest. Coloration uniform. 



Brazil, Guiana. 



a. Eight inches long. Guiana. Presented by Sir R. Schomburgk. 



b. Young. River Capin, Para. Purchased of Mr. Stevens. 



c-f. Adult, half-grown, and young. Essequibo River. Purchased 

 of Mr. Ehrhardt. 



5. Pimelodus modestus. 



Pimelodus modestus, Giinth. Proc. Zool. Soc. 1800, p. 2.39. pi. 10. fig.C. 

 B. 6. D. 1/6. A. 12. P. 1/8. 



Head covered with a very thin membrane above ; occipital process 

 narrow, elongate, extending on to the small triangular basal bone of 

 the dors;il spine. Adipose fin long, a little less than one-third of 

 the total length (without caudal) ; its distance from the dorsal fin 

 is less than the length of the latter. The maxillary barbels extend 

 to the origin of the anal fin, the outer ones of the mandible to the 

 middle of the pectoral fin. 



The height of the body is contained five times and a half in the 

 total length (without caudal), the length of the head four times and 

 two-thirds. The eye occupies the middle of the length of the head, 

 of which its diameter is one-fourth, and equal to the width of the 



* In a specimen S inches lonfj;. 



t In a specimen 1.'! inches long the dorsal is much enlarged, the second soft 

 ray being nearly twice as long as the head. 



