SOUTH AMERICAN NEMATOGNATHI. 249 



Distance of the dorsal spine from the snout 2J-2^ in 

 the length. Dorsal spine somewhat curved, IJ-lf in 

 the head, its sides finely striate, serrate in front and be- 

 hind, the anterior seme strongest. Back somewhat 

 trenchant, with a long, low, adipose fin. 



Caudal emarginate, the lobes rounded, the rays leath- 

 ery, about lf-2 in the head. 



Anal truncate, fifth ray highest, 2-2| in the head. 



Ventrals long, not reaching the anal, about as high as 

 the anal. 



Pectoral spine strong, finely striate on both sides, ser- 

 rate on both margins, reaching beyond the vertical from 

 the last dorsal ray. 



Brown; sometimes white below, the little warts on the 

 back and sides white. Sides and belly sometimes with 

 darker spots. Fins dark brown, sometimes spotted at 

 the base. Young light brown, spotted with darker. 



Head 3-3J; depth 5; Lat. 1. 17-25; D. I, 6; A. 11-12; 

 V. 7; P. I, 10. 



Sixteen specimens .135-. 44 m. Teffe (prionomus); 

 Gurupa; Manacapuru; Coary; Obidos. 



186. Oxydoras knerii. 



Doras (Oxydoras} niyer Kner, SB. Ak. Wien, xvii, 1855, 146, not 



Val. (Cujaba), 

 Oxydoras knerii Bleeker, Nederl. Tijdschr. Dierkunde, i, 12 and 



14, 1863 (name only). 

 Rhinodoras knerii Giiiither, Cat. Fish. Brit. Mus. v, 209, 1864 



(copied). 

 Habitat: Cujaba. 



187, Oxydoras d'orbigny, 



Doras (Oxydoras) d'orbigny (Kroyer), Kner, SB. Ak. Wieu, xvii, 



149, pi. v, fig. 9, 1855 (Kio Plata). 

 Oxydoras d'orbigny Eigenin. & Eigeiim. Proc. Cal. Acad. 2d Ser. 



i, 159, 1888. 

 Doras d orbignii Hyrtle, Deiik. Ak. Wieu, xvi, 17, 1859 (vertebr.i 



6+4+21). 

 Rhinodoras orbignyi Bleeker, Nederl. Tijdschr. Dierkunde, i, 14, 



1863 (name only); Giinther, Cat. Fish. Brit. Mus. v, 209, 1864 



(copied). 

 Habitat: Rio de la Pl.t i. 



