ElGENMANN I THE EXPEDITION TO BRITISH GUIANA. 5 



at VVarraputa Cataract ; Essequibo River opposite the mouth of the 

 Konawaruk River; Essequibo River at Crab Falls ; Essequibo River 

 at Rockstone ; Tributary of Essequibo River, on Gluck Island, Rock- 

 stone ; Bartica ; Demarara River at Malali ; Demarara River at Wis- 

 mar ; Demarara River at Christianburg ; Christianburg Canal ; De- 

 marara River near Freiheit ; Demarara River at Georgetown, George- 

 town Market ; Upper Potaro River at Aruataima Cataract ; Tributaries 

 of Upper Potaro River at Holmia ; Upper Potaro River at a sand-bank 

 two hours below Holmia ; Upper Potaro River at Savannah Landing ; 

 Shrimp (Orimetuk) Creek ; Lower Potaro at Tukeit ; Lower Potaro at 

 Waratuk Cataract ; Lower Potaro at Amatuk Cataract ; Lower Potaro 

 at Kangaruma ; Erukin Creek near confluence with the Lower Potarc ; 

 Creek near Potaro Landing ; Lower Potaro at Tumatumari ; George- 

 town Trenches and Botanic Garden Trenches ; Cane Grove Corner ; 

 Lama Stop-off and Maduni Stop-off about twenty-five miles east of 

 Georgetown ; Moro Passage ; creeks and trenches about Koriabo Rub- 

 ber Plantation ; and Aruka River in the northwestern territory near the 

 Venezuelan frontier. 



The type specimen and a series of other specimens of each species 

 are deposited in the Carnegie Museum at Pittsburgh. A full series is 

 also retained in the collections of the Indiana University. In the 

 following pages C. M. following a number refers to the collections of 

 the Carnegie Museum ; I. U. refers to those of the Indiana University. 



Order NEMATOGNATHI. 



Family LORICARIID^. 



Corymbophanes gen. nov. 



Allied to Rhinelepis. No adipose fin, the fin replaced by a low 

 median ridge extending from the tip of the dorsal to the caudal ; no 

 externally visible occipital crest. 



Corymbophanes andersoni sp. nov. 



Type unique, 86 mm. (No. iooi Carnegie Museum Catalog of 

 Fishes. ) Aruataima Falls, Upper Potaro. 



Head 3^3 in the length, measured to end of opercle and end of the 

 lateral plates ; depth 6; D. 1,7; A. 1,4; V. 1,5; P. 1,6; lat. 1. 24 ; 

 eye 5}^ in snout, 7^ in head to end of opercle, 3 in interorbital. 



Oral disk everywhere thickly papillose, the papillae largest along the 

 margin of the upper lip and smallest at the angle of the mouth ; barbel 



