344 cnARACixiD^. 



Characinus argentinus, Lavep. v. p. 272. 



Piabuca argentina, Cuv. Rh/ne Anhn. ; Midi. <^ Trosch. Hor. Ichth. i. 

 p. 9. taf. 1. fig. 1 ; Cuv. ^ Val. xxii. p. 108. 



B. 4. D. 11. A. 46. V. 8. L. lat. 82. 



The length of the head is equal to, or less than, the height of the 

 body, which is one-fifth or one-sixth of the total length (with the 

 caudal). A silvery band along the side, above the lateral line ; a 

 black spot at the base of the caudal fin. 



Brazil; Surinam. 



2. Piabuca spilurus. 

 D. 10. A. 32. V. 8. L. lat. 57. 

 The height of the body is one-sixth of the total length (without 

 caudal), the length of the head one -fifth. Fourteen crenulated teeth 

 in the upper jaw as well as in the lower. The origin of the dorsal 

 fin is midway between the occiput and the root of the caudal, and 

 somewhat in front of that of the anal. Silvery iridescent ; caudal 

 with a large rounded deep-black spot on its basal portion. 

 Amazons. 



a. Two and a half inches long. River Cupai. Purchased of Mr. 

 Stevens. 



31. AGONIATES. 



Agoniates, Midi. <^ Trosch. Hen-. Ichth. i. p. 33. 



Dorsal fin placed behind the middle of the length of the body, 

 behind the ventrals ; anal rather long. Body oblong, covered with 

 scales of moderate size ; belly strongly compressed. Cleft of the 

 mouth veiy wide. Intermaxillary with a double series of teeth : the 

 outer ones conical, the inner tricuspid ; maxiUarj' long, with a single 

 series of conical teeth of equal length ; mandible with strong teeth in 

 a single series, some of which are canine teeth ; a large canine tooth 

 on each side anteriorly, received in a groove on the palate ; there are 

 a few tricuspid teeth between the anterior canine teeth ; no palatine 

 teeth. Gill-openings wide ; the gill-rakers of the first branchial 

 arch setifonn. 



British Guiana. 



1. Agoniates haleciuus. 



Mull. Sf Trosch. I. c. tab. 7. fig. 2 ; Cuv. ^ Val. xxii. p. 347. 

 B. 4. D. 11. A. 20. V. 7. L. lat. 39. 



The height of the body is somewhat less than the length of the 

 head, which is contained four times and two-thirds in the total 

 (without caudal). The last dorsal rays are above the origin of the 

 anal fin. Silvery. (M. 4- T.) 



British Guiana. 



