228 viscES. 



Anostomus, Cuv. 



The form of a Thymallus and an upper and lower range of small 

 teeth; the lower jaw turned up in front of the upper one and gib- 

 bous, so that the little mouth resembles a vertical slit on the end of 

 the snout.(l) 



Gasteropelecus, B1. — Sejjpes, Lacep. 



The mouth directed upwards as in Anostomus; but the belly is 

 compressed, projecting, and trenchant, owing to its being supported 

 by ribs which terminate in the sternum; ventrals very small and far 

 back; first dorsal over the anal which is long; conical teeth in the 

 upper jaw, trenchant and dentated ones in the other. (2) 



Plabuous, Cuv. 



The small head and slightly cleft mouth of the Curimatse; a com- 

 pressed body; the ventral carina trenchant but entire, and a very 

 long anal; the first dorsal opposite to the commencement of the lat- 

 ter.(3) The 



Serrasalmus, Lacep., 



Already distinguished by that naturalist, is known by the com- 

 pressed, high body, and the trenchant and serrated belly, to which 

 characters must be added that of the triangular trenchant and den- 

 tated teeth. The edentated maxillary passes obliquely over the 

 commissure. There is frequently a horizontal spine in front of the 

 dorsal. 



The species known are all from the rivers of South America. 

 It is said that they pursue ducks, and even men, while bathing, 

 inflicting severe wounds with their sharp teeth. (4) 



Tetragonopterus, Artedi. 



The long anal, and trenchant, dentated teeth of the Serrasalmi, 

 and the edentated maxillary passing obliquely over the commissure; 



(1) Salmo anostomus, L., Gronov., VIII, 2. 



(2) Gastropelecus sternida,^\.,97,?>. 



(3) Salmo argentinus, IJl., 382, 1; Marcgr., 170; — S. bimaculatus, Bl., 16; — S. 

 gibbosus, Grouov., Mas., I, i, 4; — S. 7nelcmurus, Bl. 3S1, 2. 



(4) Salmo rlwmbo'ides, 151., S8:i;—Se>ras. piraya, Cuv., Mem. Mus., V, pi. xxviii, 

 f. 4; — Serras. mento, Id.jlb., f. 3; — Serras. aureus, Splx, XXIX; — S. nigricans. Id., 

 XXX. 



