28 Annals of the Carnegie Museum. 



the anterior longer ones ; ventrals very short, not reaching anal, a little 

 nearer to the snout than the dorsal ; pectorals reaching ventrals. 



Markings in formalin specimens: each pore of the lateral line sur- 

 rounded by black,- the dots forming a conspicuous line ; bases of two 

 rows of scales below the lateral line over the abdomen and three or 

 four rows of scales above the lateral line dark, the spots forming fainter 

 longitudinal lines ; margins of scales of the upper parts of the sides 

 and the entire dorsal line very dark ; a faint comma-shaped vertical 

 humeral spot interrupted in the middle ; a dark lateral band intensi- 

 fied in spots and ending in a caudal spot, which extends from a little 

 above the lateral line to the lower margin of the caudal ; ventral fins 



dusky. 



Genus Phenacogaster Eigenmann. 



Phenacogaster megalostictus sp. nov. 



Type, 65 mm. (No. 1056 Carnegie Museum Catalog of Fishes. 

 Tumatumari, Lower Potaro River. 



Cotypes, 59 specimens, 42—77 mm. Tumatumari, Lower Potaro 

 River. (C. M. Cat. No. 1057, a-j '; I. U. Cat. No. 11746.) 



Cotype, 1 specimen, 55 mm. Tukeit, Lower Potaro. (C. M. No. 

 1058.) 



Cotypes, 5 specimens, 46-64 mm. Sand bank at Tukeit. (C. M. 

 No. 1059; I. U. Cat. No. 11747.) 



Cotypes, 4 specimens, 68-85 mm - Amatuk, Lower Potaro. (C. 

 M. No. 1060; I. U. Cat. No. 11748.) 



Cotypes, 16 specimens, 41-64 mm. Crab Falls, Essequibo. (C. 

 M. No. 106 1, a-e ; I. U. Cat. No. 11 749.) 



Cotypes, 18 specimens, 36-64 mm. Rockstone, Essequibo. (C. 

 M. No. 1062, a-e\ I. U. Cat. No. 11750.) 



Head 3.8-4; depth about 2.66; D. 11; A. 33.37, usually 35 or 

 36 ; 8 scales 6-33 to 36 9 -4 to 5 ; eye 2.33-2.66 ; interorbital 3^-4. 



Elongate rhomboidal, heavy forward, the tail much compressed ; 

 profile compressed over the eye, arched in front of the dorsal ; pre- 

 ventral area flat, with two series of large scales overlapping along the 

 middle, a small scale in the angle of each pair of the overlapping scales, 

 except the two pairs between the pectorals ; midline of postventral area 

 naked ; predorsal area bluntly keeled, with about ten median scales. 



8 Of those examined three with 33, four with 34, six with 35, seven with 36 and 

 two with 37. 



9 Of those examined two with 33, three with 34, eight with 35, ten with 36. 



