58 Annals of the Carnegie Museum. 



scales in the lateral line heavily outlined with dusky and a group of 

 large chromatophores just behind the eye on the head give the appear- 

 ance of a humeral spot. Web of distal half of dorsal, almost all 

 of the caudal, all of the ventrals, pectorals, and the web between the 

 first seven anal rays dusky. Often a faint little dark spot at the base 

 of each caudal lobe, no true caudal spot. Scales of the back and 

 upper one-third of the sides outlined with dusky. A broad stripe 

 extending from the head to the caudal and half way to the end of the 

 middle Caudal rays without chromatophores, cherry-red in life. 

 Below this lateral stripe a dusky stripe two scales in width extends 

 the length of the body. The belly and a streak on the sides from just 

 above the bases of the anterior ten anal rays to the mandible without 

 chromatophores. Bases of the anal and under side of the caudal 

 peduncle black to dusky. Lips dusky. Dorsal lobe and upper part 

 of the iris cherry-red in life. 



Hemigrammus rodwayi sp. nov. 



Type, 46 mm. (No. 1450 Carnegie Museum Catalog of Fishes.) 

 Georgetown trenches. 



Cotypes, 183 specimens, 38-49 mm. Georgetown trenches. (C. 

 M. Cat. No. 1451, a-z; I. U. Cat. No. 11906.) 



Cotypes, 112 specimens, 28-53 mm - Botanic Garden. (C. M. 

 Cat. No. 1452, a-z; I. U. Cat. No. 11907.) 



Cotypes, 4 specimens, 24-26 mm. Mud Creek in Aruka. (C. 

 M. Cat. No. 1453, a-b; I. U. Cat. No. 11908.) 



Cotypes, 7 specimens, 34-40 mm. Creek in Barima River. (C. 

 M. Cat. No. 1454, a-b; I. U. Cat. No. 11909.) 



Distinguished from H. matei by not having the iridescent spot on 

 the caudal peduncle. Fins without definite black markings, some- 

 times dusky. Caudal spot well extended upon the caudal rays. A 

 bright cherry-red spot at the base of each caudal lobe in living males ; 

 this same color is very often found on the base of the dorsal and anal. 

 The red is replaced in females with yellow. 



Head 4, depth 2.75-3, D 11, A 22-24; scales 5-32 to 34-2-J- to 

 3J ; eye 2-2^ in the head ; snout \ of the eye, interorbitals very 

 nearly equal to the eye, 2.4 to 2.5 in the head. 



Compressed, head at the base of occipital process \ to -J of the 

 greatest depth. Preventral region rounded without complete series 

 of median scales. Postventral region narrow. Predorsal region 



