SOUTH AMERICAN NKM ATOGNATHI. 23 



11, Platystacus nematophorus, 



Platystacus nematophorus Bleeker, Silures de Suriname, 96, pi. i, 

 fig. 1, 1864 (Surinam); E. & E. Proc. Cal. Acad. Sci. 2d Ser. ii, 

 1889, 50. 



Aspredo nematophorus Giinther, Cat. Fish. Brit. Mus. v, 270, 1864 

 (copied). 



Habitat: Surinam. 



12. Platystacus aspredo. 



Silurus aspredo Linnseus, Syst. Nat. Ed. x, 304, 1758; Ed xii, 502, 

 1766; Bonnaterre, Tableau Encycl. Ichthyol. 150, 1788; Lac- 

 epede Syst. Ichthyol. v, 78, 1803. 



Platystacus aspredo E. & E. Proc. Cal. Acad. Sci. 2d Ser. ii, 1889, 

 50 (Para; Arary). 



Platystacus Icnvis Bloch, Ausl. Fische viii, 58, 1794; Bloch & 

 Schneider, Syst. Ichthyol. 373, 1801. 



Aspredo lavis Cuv. & Val. Hist. Nat. Poiss. xv, 431, 1840 (Guiana); 

 Miiller & Troschel, Schomburgk's Brit. Guiana, 630, 1848 

 (Waini). 



Aspredo batrachus (Linnasus Mus. Ad. Fred. 73) Gronow, "Cat. 

 Fish." 137, 1854; Bleeker, Silures de Suriname, 93, 1864 (Suri- 

 nam); Giinther, Cat. Fish. Brit. Mus. v, 269, 1864 (British 

 Guiana; Cayenne; Surinam). 



Habitat: Guiana; Kio Para and Lake Arary. 



Head greatly depressed, spatulate; interorbital width 

 3J in the distance from base of pectoral to tip of snout. 

 Mouth broad, the snout projecting almost its entire 

 length; each jaw with two patches of small teeth. Max- 

 illary barbel reaching to base of pectoral, an accessory 

 barbel in front; mental barbels placed near the lip, ex- 

 tending to the postmental, which is equal to the inter- 

 orbital. 



Coracoid processes slightly diverging backward, the 

 length equal to the space between them. 



A minute pectoral pore at the extremity of the cora- 

 coid process. Humeral process a little longer than the 

 coracoid process and overlapping it. 



Distance of dorsal fin from tip of snout 3f in the 

 length; first ray rarely prolonged. Outermost caudal 

 rays slightly produced. Pectoral spine as in A. tibicen. 



Dorsal surface uniform purplish brown, the ventral 



