eigenmann: the FRESHWATER FISHES OF BRITISH GUIANA 229 



of the barbel; free part of barbel equaling eye; a narrow free membrane from the 

 barbel margining the lip outside of the incised inner margin from the barbel to a 

 point behind the angle of the mouth. 



Dentary with two teeth, each with two widely diverging cusps; premaxillary 

 with eight teeth, each with two nearly parallel cusps, of which the inner one is 

 much the longer. 



Origin of the dorsal above the middle of the ventrals, the first ray not much 

 more than half as long as the second, not spinous, the highest ray a little less than 

 the snout; spine of the adipose two-fifths of the length of the snout, covered with a 

 few spinules, its tip nearly reaching end of base of adipose part of the fin; caudal 

 rather deeply emarginate, the lower lobe the longer; origin of anal half-way between 

 tip of dorsal and origin of adipose; outer ventral ray very thick and fleshy, covered 

 with spines, its base much wider than that of the rest of the fin, reaching a little 

 more than half-way to anal, its length equal to the snout; pectoral reaching to near 

 tip of ventrals, its spine not much larger than the rest of the rays, with a few prickles. 



Naked except for a double series of plates along the ventral surface of the 

 caudal peduncle from near the tip of the anal, which curve up on either side of the 

 caudal to the base of the middle rays; about fourteen platelets along the middle of 

 the sides from above the origin of the anal to the base of the middle caudal rays, 

 widest above the tip of the anal, where they are a little wider than the eye; a double 

 series of plates on the back, beginning on either side of the spine of the adipose 

 to the caudal; outer caudal rays with prickles, a few spinelets on the caudal. 



A dark band from the eye forward, increasing in width to above the base of 

 the maxillary; back and upper part of sides marbled; caudal dark, the outer rays 

 lighter. 



For comparison I have added a figure of the Neoplecostomus granosus (Plate 



XXVI, fig. 5). 



Corymbophanes Eigenmann. 



Corymbophanes Eigenmann, Ann. Carnegie Mus., VI, 1909, 5. 



Type, Corymbophanes andersoni Eigenmann. 



Allied to Rhinelepis. No adipose fin, this being replaced by a low median 

 ridge, extending from the tip of the dorsal to the caudal; no externally visible 

 occipital crest. 



96. Corymbophanes andersoni Eigenmann. (Plate XXVII, figs. 1-3.) 

 Corymbophanes andersoni Eigenmann, Ann. Carnegie Mus., VI, 1909, 5. 



Type unique, 86 mm. Aruataima Falls, Upper Potaro. (Carnegie Museum 

 Catalog of Fishes No. 1001.) 



