SOUTH AMERICAN NEMATOGNATHI. 161 



209. Doras longipinnis Steiadachuer. 



? Doras crocodili Humbolrlt. 



210. Doras albomaculatus Peters. 



211. Doras helicophilus Giintlier. 



212. Doras dentatus Kner. 



213. Doras COStatuS (Linnaens). 



Localities: Eio Puty; RioPreto; Sau Gouijallo; Xiugu Cascade; Obidos; 

 Gunipa; Teflfe. 



214. Doras armatulus Guv. & Val. 



215. Doras hancockii Cnv. .fe Val. 



216. Doras brachiatus Cope. 



§ Acanthodoras. 



217. Doras calderonensis Vaillant. 

 Doras depressus Steiudachuer. 



218. Doras cataphractus (Liuureus.) 



Calaphractiis americanus Bloch & Scliueider; Doras blochii Cuv. & 

 Val.; ? Doras bninnescens Schomburgk; Doras polyramma d: poly- 

 gramma Heckel; Cullichthys asper Gronow. 



219. Doras spinosissimus sp. uov. 



Type, No. 7222, oue specimen .15 m. Coary. Professor L. Agassiz. 



Short and thick, the width below the dorsal spine greater 

 than the depth; caudal peduncle little deeper than wide. 

 Head as broad as long, its depth 1 J in its length : top of 

 head, opercle, preopercle and suborbitals finely granular; 

 the nasal bones with their free margin spinous. Top of 

 head broad and flattish. Dorsal plate broad, without 

 prominent downward or backward processes. Sutures of 

 the skull marked by smooth lines. Fontanel reduced to a 

 small oval opening surrounded by granulations. 



Eye 1| in the snout, 7 in the head, 3 in the interorbital. 



Maxillary and post-mental barbels reaching to the pec- 

 toral pore; mental barbels f as long as the post-mentals. 



Snout broad, its width at the rictus 1| in the head. Jaws 

 subequal; teeth minutely villiform, the intermaxillary band 

 six times as wide as deep. 



