eigenmann: the freshwater fishes of British guiana 213 



Type, 41 mm. Amatuk. (Carnegie Museum Catalog of Fishes No. 2212.) 



Cotype, 34 mm. Waratuk. (I. U. Cat. No. 11710.) 



These specimens were considered identical with guianense. The discovery of 

 Pygidium gracilior makes it very probable that they are distinct. The differences 

 are pointed out in the key. 



This species is named for Mr. Bernard S. Conrad. 



84. Pygidium gracilior sp. nov. 



Type unique, 27 mm. Erukin. (Carnegie Museum Catalog of Fishes 

 No. 1730.) 



Head 6; depth 9; D. 8; A. 6; eye about 2 in the snout; interorbital a little 

 greater than snout, snout 3 in the head. 



Slender, head as broad as long; maxillary barbel reaching tip of pectoral; 

 nasal barbel to origin of pectoral; outer pectoral ray prolonged, about equal to 

 the head in length. Origin of the anal under origin of dorsal; distance from origin 

 of dorsal to origin of caudal 3.5 in the length; length of caudal 5 in the length. 



All upper parts obscurely spotted. 



Subfamily STEGOPHiLiNiE. 

 Ochmacanthus 21 gen. nov. 



Type, Ochmacanthus flabelliferus sp. nov. 



In the Annals of the Carnegie Museum, IV, 118, I called attention to the fact 

 that Stegophilus insidiosus and Stegophilus reinhardti "differ much from each other 

 in the caudal fulcra and may represent two distinct genera." A new species from 

 Guiana with the structure of reinhardti may be utilized to furnish a diagnosis of 

 the new genus. 



Two maxillary barbels, one of them minute; mouth large, wholly inferior; dorsal 

 over anal; fully developed caudal rays much diverging from a narrow base; caudal 

 fulcra greatly developed; eye above the mouth. 



85. Ochmacanthus flabelliferus sp. nov. 

 Type, 33 mm. Konawaruk. (Carnegie Museum Catalog of Fishes No. 1729.) 

 Cotypes, two specimens, 34 and 35 mm. Konawaruk. (I. U. Cat. No. 12111.) 

 Head 5.33; depth 7; D. 8; A. 7; eye 1 in snout, 3.75 in head, 1 in space 



between the eyes. 



Width of head equal to its length; snout semicircular in outline, the head 



depressed; mouth very wide, its width equal to the length of the head less half the 



21 flx/uos, series, inavda, thorn. 



