146 CALIFORNIA ACADEMY OF SCIENCES. 



of the head; each jaw with a band of strong villiform 

 teeth. 



Origin of dorsal fin from tip of snout 3J in the length. 



Adipose fin long and low, its origin in advance of the 

 anal, confluent with the caudal fin. Caudal with num- 

 erous accessory rays, widely forked, its upper lobe longer, 

 about 5J in the length. Origin of anal a little nearer 

 base of caudal than to gill opening, the rays of about 

 equal height. Ventrals high and narrow, inserted be- 

 low the first dorsal ray. Pectorals long and narrow, 

 scarcely shorter than the head, the middle rays longest. 



Brownish, with traces of a dark lateral band; a dark 

 bar extending forward from the eye; two dark lines on 

 base of caudal and parallel with its root. 



Head 7J; depth 10; D. 7; A. 19. 



105, Acentronichthys surinamensis, 



Heptapterus surinamensis Bleeker, Silures de Suriname, 91, pi. xv, 

 fig. 1, 1864 (Surinam); Giinther, Cat. Fish. Brit. Mus. v, 271, 

 1864 (copied). 



Habitat: Surinam. 



This species is known from the types only. 



106, Acentronichthys collettii, 



Heptapterus collettii Steindachner, Flussfische Sudani, iii, 7, pi. v. 



fig. 1, 1881 (Maldonado). 

 Habitat: Mouth of the Rio Plata in brackish water. 



This species is known from the types only. 



XIX. NANNOGLANIS. 



Nannoglanis Boulenger, Proc. Zool. Soc. Lond. 278, 

 1887 (fasciatus). 



A. 8. Adipose fin present; dorsal fin without a pun- 

 gent spine and placed behind the ventrals. Barbels six; 

 Fontanel ? Occipital process ? 



We have not seen the only known species of this ge- 

 nus but its general structure is so much like that of 

 Heptapterus and Rhamdella that we think we are war- 



