42( ORDER MALACOPTERYGII ABDOMINALES. 



Serra-salmes, Lacep*, 



Already distinguished by M. de Lacepede ; body com- 

 pressed, high vertically, and the belly trenchant, and 

 dentated like a saw, characters to which it is necessary 

 to add that of their triangular, trenchant, and dentated 

 teeth. The maxillary without teeth crosses the com- 

 missure obliquely. There is frequently a couchant 

 spine in the front of their dorsal. 



Those which are known come from the rivers of 

 South America. It is said that they pursue ducks, 

 and even men who are bathing, and tear away their 

 skin with their trenchant teeth \ 



Tetragonopterus, Artedi, 



Have the anal long, and the trenchant and dentated 

 teeth of the serra-salmes ; the maxillary without teeth, 

 in like manner, crosses the commissure obliquely ; 

 but the mouth is but slightly cleft, and the belly is 

 neither carinated nor dentated 2 . 



Chalceus, Cuv., 

 Have the same form of mouth, and the same trenchant 



1 Salmo rhomboides, Bl. 383. Serr. piraya, Cuv., Mem. Mus. 

 V. pi. xxviii. f. 4. Serras. mento, Id. ib. f. 3. Serr. aureus, Spix, 

 xxix. S. nigricans, Id. xxx. 



2 Tetragonopteros argenteus, Artedi. Ap. Seb. III. pi. xxxiv. f. 3. ; 

 or Coregono'ides Amboinensis, Art. Spec. 44, which has been errone- 

 ously confounded with Salmo bimaculatus. Chalceus fascialus, Cuv., 

 Mem. Mus. V. pi. xxvi, f. 2. Serra-sahno chalceus, Spix, 

 xxxiii. 1. 



