SOUTH AMERICAN NEMATOGNATHI. 231 



the dorsal fin, much longer in old. Adipose fin longer 

 than the dorsal fin, becoming gradually lower in front, 

 shorter than dorsal in old. 



Caudal long, deeply forked, 3J in the length. 



Anal fin much higher than long, obliquely truncate, 

 the 4th ray highest, 1J in the head. 



Ventrals reaching the anal fin, 1J in the head. 



Pectoral spine long and strong, reaching to below 3d 

 dorsal ray, almost smooth on sides, strongly serrate on 

 both margins. 



Rusty brown, lighter below; fins and back with round 

 brown spots. 



Head 4-4J; depth 4-4J; D. I, 6; A. 12; V. 7; P. I, 8. 



Five specimens .24-.92 m. Arary?; Uruguay; Buenos 

 Ay res; Serpa. 



164. Doras longispinis, 



Doras longispinis Steindachner, Fisch-fauna, Magd. Stromes, 23, pi. 

 iv, fig. 2, and pi. i, fig. 1, 1879 (Magdalena River); Steindach- 

 ner, Fisch-fauna des Cauca & Fliisse bei Guayaquil, 11, 1879 

 (Cauca). 



Habitat: Eio Magdalena and its tributaries. 



165. Doras albomaculatas. 



Doras albomaculatus Peters, MB. Ak. Berl. 470, 1877 (Calabozo). 

 Habitat: Calabozo, Venezuela. 



166. Doras helicophilus. 



Doras helicophilus Giinther, Proc. Zool. Soc. Lond. xxxvii, 229, 1868 



(Surinam). 

 Habitat: Surinam. 



167. Doras dentatus. 



Doras dentatus Kner, SB. Ak. Wien, xvii, Ichthyol. Beitr. 118, plate 

 iii, fig. 3, 1855 (Surinam); Giinther, Cat. Fish. Brit. Mus. v, 201, 

 1864 (copied). 



Habitat: Surinam. 



168. Doras costatus. 



Silurus costatus Linnaeus, Syst. Nat. ed. xii, 506, 

 Cataphraclus costatus Bloch, Auslandische 

 376, 1794. 



