15. LEPORINUS. 309 



extremity of the snout ; incisors broad, truncated. The pectoral 

 terminates at some distance from the ventral. Coloration uniform. 

 Rio Araguay, Rio Cipo. 



a. Adult: skin. Eio Cipo. Presented by Ch. Cumberland, Esq. — 

 Vernacular name : Piao. 



9. Leporinus margaritaceus. 

 D. 12. A. 11. V. 10. L. lat. 39. L. transv. 6/6. 



The height of the body equals the length of the head, and is one- 

 fifth of the total (without caudal). The eye is a little nearer to the 

 end of the operculum than to the extremity of the snout ; its dia- 

 meter is two-thirds of the width of the interorbital space, and one- 

 fourth of the length of the head. Lips rather thick, not fringed. 

 Teeth rather narrow, the lower obliquely truncated. The distance 

 of the first dorsal ray from the extremity of the snout equals that 

 from the adipose fin. Anal rays long, reaching beyond the root of 

 the caudal if laid backwards. Coloration uniform, each scale with 

 a broad pearl-coloured margin ; an indistinct yellowish band along 

 the side of body and tail, below the lateral line. 



British Guiana. 



a. Eight and a half inches long. Presented by Sir R. Schomburgk. 



10. Leporinus elongatus. 

 Cuv. 8f Val. xxii. p. 37. 



D. 12. A. 11. V. 9. L. lat. 42. 



Body elongate, its height being one-fifth of the total length (with 

 the caudal ?) ; the anal fin does not extend to the root of the caudal 

 if laid backwards. Coloration uniform, each scale with a broad 

 darker margin. ( Val.) 



Rio San Francisco, Rio de la Plata. 



11. Leporinus nigro-taeniatus. 



Chalceus nigrotseniatus, Sclwmb. Fish. Guian. i. p. 213. pi. 13. fig. 2. 

 Leporinus nigrotaeniatus, Midi, fy Trosch. Hor. Ichth. i. p. 11. tab. 1. 

 fig. 7 (dentition) ; Cuv. 8f Val. xxii. p. 32. 



D. 12. A. 11. V. 10. L. lat. 42. L. transv. (i/6. 



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

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

 total ; the eye is somewhat nearer to the end of the operculum than 

 to the extremity of the snout ; anterior teeth with a narrow brownish 

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

 A black band commences below the dorsal fin, and runs along the 

 lateral line to the base of the caudal fin. 



British Guiana. 



a-b. Fine specimens. Essequibo. From Mr. Ehrhardt's. Collection, 

 o. Adult : skin. Presented by Ch. Cumberland, Esq. 



