SOUTH AMERICAN NEMATOGNATHI. 319 



aaa. Teeth on the intermaxillaries aud on the mandible villiforiu, in bauds, 

 those on the vomer conical, in a single series. (Pseudocetopsis). 



c. Eye moderately large, about 6 in the head; gill-opening as far above 

 as below the pectoral. Distance of the first dorsal ray from tip of 

 suout 3 in the length; ventral fins united by a membrane; pectoral 

 fins reaching in theS beyond the base of the ventrals. All fins im- 

 maculate. Head 5; dorsal 7; A. 22. (Kner.) . gohloides '252. 



aaaa. Teeth all villiform. 



d. Teeth on the vomer in two patches; head 3L Ventrals behind the 

 vertical from the last dorsal ray, the basal half of the inner margin 

 joined to the ventral surface; jiosterior nares remote from each other. 

 Eye lOf in the head. Barbels all short. Gill-opening extending 

 above and below the pectoral fin. Distance of first dorsal ray from 

 tip of snout 2^ in the length. Caudal somewhat forked; pectoral fin 

 reaching f toward the base of the ventrals. Depth 4; D. I, 6; P. I, 9; 

 V. I, 5; A. 29. (Steindachner). occidentali.'i 253. 



dd. Teeth on the vomer in a single series; head 4^; width of the head 

 not more than half of its length; ventral fins connected by their inner 

 margins to the ventral si;rface. Barbels all short. Grayish, darker 

 above; basal half of the dorsal punctate with black. D. I, 6; A. 29; 

 V. 6; P. 10. (Gill.) centralis 254. 



249. Cetopsis candiru. 



S/Iurus candiru Spix. Gen. Spec. Pise. 13, plate x, fig. 1, 1829 (Equa- 

 torial rivers of Brazil). 



Cetopsis candiru Agassiz, Gen. Spec. Pise. 13, 1829. 



Cetopsis candira Guv. & Val. Hist Nat. Poiss.xiv, 386, 1839 (copied); 

 Gilnther, Cat. Fish. Brit. Mus. v, 199, 1864 (KiverCupai); Cope, 

 Proc. Am. Philos. Soc. xvii, 678, 1878 (Peruvian Amazon); Stein- 

 dachner, Flussfische Stidamerika's, iv, 5, 1882 (Rio Huallaga); 

 Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 157, 1888 (Taba- 

 tinga; Jutahj', Tonantins; Iga). 



Habitat: Amazons and tributaries from the Eio Cupai to the Kio 

 Huallaga). 



Subterete, little compressed and scarcely tapering- 

 backward. Head short and thick, the bones everywhere 

 covered with thick muscle; profile somewhat arched in 

 front; the depth of the head a little less than the width; 

 anterior nares li times as wide apart as the posterior 

 ones. 



Eye small, but much larger than one of the posterior 

 nares. 



Barbels rather thick and short, at least partially re- 



