188 MEMOIRS OF THE CARNEGIE MUSEUM 



surface with three sharp ridges, its lower striate, reaching past base of ventrals; 

 dorsal spine shorter than pectoral spine, with four sharp ridges on each side and a 

 median one in front, the latter sometimes broken up into teeth near the base of the 

 spine; caudal truncate, very slightly emarginate or rounded; humeral process with 

 lines of granules, which become stronger along the lower margin, and recurved spines 

 towards its tip. 



Lateral plates regularly decreasing in height backward, each with a strong- 

 recurved hook, and ridges above and below which end in spines; caudal fulcra 

 extending forward above and below on the caudal peduncle, but the latter largely 

 naked. 



Ash-colored; head and body variously marked with black; an irregular black 

 band along sides below the median hooks. A black spot at base of caudal; three 

 more or less distinct black blotches on the back; one down and behind dorsal, 

 one about adipose and one across caudal peduncle; dorsal and caudal, and to less 

 extent the remaining fins, marked with black; lower surface variously marked. 



59. Doras cataphractus (Linnaeus). 



Silurus cataphractus Linn^us, Syst. Nat., ed. 10, 1, 1758, 307; ed. 12, 1, 1766, 506. 

 Doras cataphractus Cuvier and Valenciennes, Hist. Nat. Poiss., XV, 1840, 276 



(?).— Kner, SB. Akad. Wiss. Wien, XVII, 1855, 126 (Rio Guapore; Barra do 



Rio Negro). — Bleeker, Ichth. Arch. Ind. Prodr., I, 1858, 54. — Gunther, 



Catalogue, V, 1864, 204 (?). — Eigenmann and Eigenmann, Occasional Papers 



Cal. Acad. Sci., I, 1890, 234. — Eigenmann, Repts. Princeton Univ. Exp. 



Patagonia, III, 1910, 393. 

 Acanthodoras cataphractus Bleeker, Nederl. Tijdschr. Dierk., I, 1863, 17; " Silures 



de Suriname," 1864, 40 (Surinam). 

 Cataphractus americanus Bloch and Schneider, Syst. Ichth., 1801, 107, pi. 



28.— Lacepede, Hist. Nat. Poiss., V, 1803, 124, 127 (Carolina?). 

 Doras blochii Cuvier and Valenciennes, Hist. Nat. Poiss., XV, 1840, 277 (copied). 

 ? Doras castaneo-ventris Schomburgk, Fishes Brit. Guiana, I, 1841, 161, pi. 3 (Rio 



Pasawiri) . 

 ? Doras brunnescens Schomburgk, Fishes Brit. Guiana, I, 1841, 163 (Upper 



Essequibo) . 

 Doras polyramma et polygramma (ex Heckel, MS.) Kner, SB. Akad. Wiss. Wien, 



XVII, 1855, 126, 127. 

 Callichthys asper Gronow, Cat. Fish., ed. Gray, 1854, 157. 



One specimen, 170 mm. Kangaruma. (C. M. Cat. No. 1640.) 



