306 CHAEACrNID,E. 



2. Rhytiodus argenteo-fascus. 

 Siier, I. c. p. 166. fig. 16. 

 D. 11. A. 11. V. 9. L. lat. 55-56. L. transv. 7/6. 

 The height of the hody is a little more than the length of the head, 

 and contained five times and one-third in the total (without caudal) ; 

 head much depressed. Brown above, silvery below. {Kner.) 

 Rio Negro, 



15. LEPORINUS*. 

 Lepoiinus, Spix, Pise. Bmsil. p. 65. 



Dorsal fin placed nearly in the middle of the length of the body ; 

 anal short ; ventrals below the dorsal. Body oblong, covered with 

 scales of moderate size ; belly rounded. Cleft of the mouth small, 

 with the lips well developed ; teeth in the intermaxillary and man- 

 dible, few in number, flattened, with the apex more or less truncated, 

 and not serrated ; the middle pair of teeth is the longest in both 

 jaws ; palate toothless. Nostrils somewhat remote from each other : 

 the posterior open, the anterior with a short tube. GiU-membranes 

 grown to the isthmus, without posterior free margin. 



South America, east of the Andes. 



1. Leporinus frederici. 



Salmo frederici, Block, taf.' 378 ; Bl. Schn. p. 403. 



Cmimatus acutidens, Valenc. in d" Orb. Voy. Amer. MSrid. Poiss. pi. 8. 



fig. 1. _ 



Leporinus frederici, Cuv. Sf Val. xxii. p. 25. 



D. 12. A. 11. V. 9. L. lat. 38-39. L. transv. 5/6. 



The length of the head is one-fourth of the total (without caudal) ; 

 the eye occupies the middle of the length of the head ; incisors with 

 the inner sm-face brown, and with the edge produced into a point. 

 The pectoral fin terminates at a great distance from the ventral. 

 Three rounded black spots along the lateral line, the first below the 

 hinder half of the dorsal, the third at the root of the caudal. 



Guianas, Brazil. 



a-h. Fine specimens. Essequibo River. From Mr. Ehrhardt's Col- 

 lection. 

 c. Young. River Cupai. Purchased of Mr. Stevens. 



2. Leporinus obtusidens. 



Curimatus obtusidens, Vaknc. in (V Orb. Voy. Amer, Merid. Poiss. pi. 8. 



fig. 2. 

 Leporinus obtusidens, Cuv. ^ Val. xxii. p. 28. 



D. 12. A. 11. L. lat. 42. 



The length of the head is one-fifth of the total (without caudal). 



* 1 . Leporinus maculatus, Mull. Sf Trosch. Hor. Ichthyol. iii. p. 1 1 ; ? Cuv. Sf 

 Val. xxii. p. 31 ; ? Casteln. Anim. Amir. 8ud, Poiss. p. 58. pi. 29. fig. 2. — 

 British Guiana ; ? Brazil. 



