SOUTH AMERICAN NEMATOGNATHI. 213 



era Platystoma and Sorubim, which, as used by them, are 

 coextensive. Bleeker first restricted the genus Sorubim 

 to the Silurus lima Bloch & Schn. ; he also restricted 

 Platystoma to the same species, making Platystoma a 

 synonym of Sorubim. The name Platystoma, however, 

 is preoccupied, and we retain the name Sorubim. 



Head abnormally depressed, the eyes perfectly lateral; 

 teeth of the upper jaw in a band which is wider than 

 deep; teeth on roof of mouth in four patches, the vo- 

 merine patches joined in the adult; barbels fleshy; adi- 

 pose fin shorter than anal; dorsal spine equidistant from 

 snout and posterior margin of adipose fin; plates on the 

 anterior portion of the lateral line. 



155, Sorubim lima. 



Silurus lima Bloch & Schneider, " Syst. Ichthyol. 384," 1801. 



Platystoma lima Agassiz, Gen. Spec. Pise. 24, 1829 (Equatorial 

 Brazil); Cuv. & Val. xv, 7, 1840 (locality?); Kuer, SB. Ak. 

 Wien, xxvi, 399, 1857 (Rio Guapore; Rio Branco; Rio Negro). 



Sorubim lima Giinther, Cat. Fish. Brit. Mus. v, 105, 1864 (copied); 

 Peters, MB. Ak. Berl. 469, 1877 (Calabozo); Steindachner, Fisch- 

 fauna des Magd. Stromes 15, 1878 (Rio Magdalena); Cope, 

 Proc. Am. Philos. Soc. xvii, 674, 1878 (Peruvian Amazon); Stein- 

 dachner, Fisch-fauna Cauca & Fliisse bei Guayaquil, 5, 1879 

 (Cauca in the province Antiochia); Vaillant. Bull. Soc. Philom. 

 Ser. 7, iv, 150, 1880 (Calderon); Steindachner, Flussfishe Sii- 

 dam. iv, 4, 1882 (Rio Huallaga); Eigenm. & Eigenm. Proc. Cal. 

 Acad. 2d Ser. i, 138, 1888 (Manacapuru; Sao Paolo; Fonte- 

 boa; Tabatinga; Hyavary; Teffe; Obidos; Maranon; Ucay- 

 ale; lea; Lago do Manimo; Para; Rio Puty; Jutahy). 



Sorubim infraocularis Spix, Gen. et Spec. Pise. Bras. pi. xv, 1829 

 (Equatorial Brazil). 



Platystoma luceri Weyenbergh, Nuevos Pescados, 10, pi. iii, figs. 

 1-3, 1877 (Santa Fe). 



Habitat: Rio Plata; Amazons and tributaries to the Rio Magda- 

 lena and its tributaries. 



Body elongate, subcylindrical; head abnominally 

 depressed, its depth 5 in its length; eye strictly lateral; 

 maxillary barbel extending past front of dorsal; mental 

 barbel extending beyond eye ; postmental slightly beyond 

 head. 



