SOUTH AMERICAN NEMATOGNATHI. 309 



-covered with dark dots; tip of dorsal and caudal blackish; 

 dorsal surface irregularly spotted with dark brown. 



Head 4|-4f; depth below dorsal 7-7 -J; above anal 

 5-l-5|; Br. 10; D. I. 6; A. 44. 



The specimens examined measure .14-. 25 m. Teffe; 

 Para; Cameta. Agassiz & Bourget. 



243. Ageneiosus porphyreus, 



Ageneiosus porphyreus Cope, Trans. Am. Philos. Soc. xiii, 404, 



1867 (Surinam). 

 Habitat: Surinam. 



This species is known to us only from the description 

 by Dr. Cope. 



244. Ageneiosus dawalla. 



Ageneiosus inermis Cuv. & Val. Hist. Nat. Poiss. xv, 240, plate 440, 



1840 (Surinam) [not Silurus inermis Linn, or Bloch]; Castelnau 



Anim. Am. Slid. 48, 1855 (Amazon). 

 Hypophthalmus dawalla Schomburgk, Fisch. Brit. Guiana, 191, pi. 



9, 1849 (Guiana). 

 Ageneiosus dawalla Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 



150, 1888 (name only). 



Ageniosus sebce Giinther, Cat. Fish. Brit. Mus. v, 192, 1864 (copied). 

 Habitat: Guiana; Amazon. 



This species has not been examined by us. H. daivalla 

 Schomburgk, evidently represents some species of Agen- 

 eiosus; in its proportions it agrees with Ageneiosus iner- 

 mis Cuv. & Val., and as it came from the same locality, 

 we may not be far wrong in identifying it with that 

 species. 



245. Ageneiosus brevifilis, 



Ageneiosus brevifilis Cuv. & Val. Hist. Nat. Poiss. xv, 242, 1840 (Cay- 

 enne); Kner, SB. Ak. Wien, xxvi, 438, 1857 (Kio Cujaba); Giin- 

 ther,Cat. Fish. Brit. Mus. v, 192, 1864 (Kiver Capin, Para); 

 Giinther, Proc. Zool. Soc. Lond. 229, 1868 (Xeberos); Cope, 

 Proc. Am. Philos. Soc. xvii, 676, 1878 (Peruvian Amazon); 

 Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 150, 1888 (Serpa). 



Pseudageneiosus brevifilis Bleeker, Silures des Suriname, 83, pi. xvi, 

 fig. 1, 1864 (Surinam). 



Habitat: Amazons; Guiana; Upper Paraguay. 



Body robust, becoming compressed backward. Head 



