THE GYMNOTID EELS OF TROPICAL AMERICA. 153 



Fig. 15. Porotergus gimbrli Ellis. 



24. Porotergus gymnotus Ellis. (Plate XXIII, fig. 4.) 



Porotergus gymnotus Ellis, in Eigenmann, Freshwater Fishes of British Guiana. 

 Mem. Carnegie Mus., Vol. V, 1912, 441. 



1759 C. M., type, 70 mm. Amatuk, Eigenmann. 



12636 I. U. M., cotype, two, 68 and 85 mm. Amatuk, Eigenmann. 



1758 C. M., cotype, one, 62 mm. Konawaruk, Eigenmann. 



Head 6 to 6.5, greatest depth 6.2 to 6.7 in the length to the end of the anal. 

 Anal rays 130-147^; snout 2.2 to 2.5 in the head, interorbital about the same; 

 eye 5 or 6 in the snout and 12 to 14 in the head; 5 to 8 rows of scales above the 

 lateral line; mid-dorsal space naked and abundantly supplied with mucous pores. 



Compressed and slender; depth of the head in occipital region 1.25 to 1.5 in 

 the greatest depth; anus not quite the length of the snout behind the vertical 

 from the eye; dorsal profile behind the head almost straight, the head sharply 

 sloping; ventral profile slightly convex, save in the mental region, where it is rather 

 concave. 



Snout heavy and somewhat truncate; mouth moderately large; gape straight, 

 not quite or barely reaching below the eye; jaws stout, lower included on the 

 sides; teeth few, smaU, conical, in two irregular interrupted rows, the inner one of 

 the lower jaw represented by but three or four teeth, two small patches of not 

 over six teeth each in the upper jaw. 



Caudal 2.8 in the head, pectorals 1.3; origin of the anal a little in front of the 

 gill-opening. 



Ground-color dark golden brown, darker dorsally; scales, anal rays, and parts 

 of the head outlined with dark brown; upper parts of the head and back, also a 

 spot at the origin of the lateral line, almost black; cheeks brown with numerous 



'Type, Amatuk, 138. Cotypcs, Amatuk, 140, 141. Cotype, Warraputa, 147. Cotype, Konawaruk, 

 130. 



