ElGENMANN : THE EXPEDITION TO BRITISH GUIANA. 43 



Pectorals reaching halfway to second third of the ventrals, ventrals 

 half way to tip of last anal ray ; origin of anal under tip of last dorsal 

 ray. No adipose fin. 



Back dark gray with a median dark line ; a light band from snout to 

 base of upper rays of middle of caudal ; a black band through mandi- 

 bles and snout to base of lower caudal and continued on the two middle 

 rays ; ventral surface plain, except for a spot between the tips of the 

 ventrals ; chromatophores of the lateral band scattered above the 

 pectorals and above the front part of the anal. 



Poecilobrycon gen. nov. 

 Type : Poecilobrycon harrisoni sp. nov. 



Poecilobrycon harrisoni sp. nov. 



Type, 55 mm. (No. 1160 Carnegie Museum Catalog of Fishes.) 

 Canal at Christianburg. 



Cotypes, 2 specimens, 45 and 51 mm. Canal at Christianburg. 

 (I. U. Cat. No. 1 1 709.) 



Head 4 ; depth 5.25 ; D. 9 ; A. 10 ; scales 5 between D. and 

 V., 26 or 27 in a median series, n or 12 in front of the dorsal; eye 

 3 in the head ; upper jaw projecting. Snout very little greater than 

 eye ; interorbital a little less than eye. 



Adipose well developed, behind tip of anal ; origin of dorsal slightly 

 posterior to that of the ventrals. Pectorals reaching half way to ven- 

 trals ; ventrals slightly more than half way to anal. 



Back chocolate ; a broad, straw-colored band from tip of snout to 

 middle of upper caudal lobe ; a narrow black band from tip of mandi- 

 ble through eye along lower part of peduncle to near tip of shortest 

 caudal ray and a few rays inferior to it. Ventral surface silvery, 

 dotted from midway of the ventrals to the anal, the dots continued 

 over the lateral band above the .anal. A spot on either side of snout, 

 the iris dorsad, a line along base of anal, and a streak above and below 

 the caudal band, crimson. An oblique, dotted bar across the yellow 

 lateral band just above tip of pectoral. Last anal rays dark. 



For J. B. Harrison, M.A., C.M.G., F.G.S., Government Geolo- 

 gist, Georgetown, British Guiana, who assisted the expedition in 



various ways. 



Poecilobrycon auratus sp. nov. 



Type, 32 mm. (No. 1161 Carnegie Museum Catalog of Fishes.) 

 Konawaruk. 



