126 MEMOIRS OF THE CARNEGIE MUSEUM. 



^« Species of Eigenmannia. 



a. Maxillary shorter than diameter of the eye; eye large; caudal filament long and ribbon-like, equal to 



about half the total length without the head macrops. 



an. Maxillary about equal to the diameter of the eye; eye medium; eaudal filament cylindrical, less than 



half the length of the anal virescens. 



aaa. Maxillary about twice the diameter of the eye; eye small; caudal filament less than half the length of 

 the anal troscheli. 



5. Eigenmannia macrops (Boulengcr). (Plate XXII, fig. 1.) 



Sternopygus macrops Boulenger, Ann. Mag. Nat. Hist. (6), XX, 305 (Potaro 

 River, British Guiana). 



Eigenmannia macrops Eigenmann and Ward, 1905, Proc. Wash. Acad. Sci., Vol. 

 VII, p. 172 (Potaro(?) River, British Guiana); Eigenmann, Repts. Princeton 

 Univ. Exp. Patagonia, III, 1910, 449 (Potaro, British Guiana). 



1804 C. M., 12601 I. U. M., thirty-two, 165-200 mm. Rockstone, Eigenmann. 



1805 C. M., 12602 I. U. M., twelve, 165-180 mm. Tumatumari, Eigenmann. 



1806 C. M., 12603 I. U. M., twelve, 125-150 mm. Crab Falls, Eigenmann. 



Head 8.25 to 9; depth 6.6 to 7.5 in the length to the end of the anal; anal rays 

 170-194.4 



Snout 3.2 to 3.4, interorbital about 3.3 in the head; eye equal to or a little 

 greater than either the snout or the interorbital and 3 or a little less in the head. 



Body and head compressed; width of the head 2.25 to 2.5, depth of the head 

 in the occipital region 1.6 to 1.8 in the greatest depth; anus on, or slightly in front 

 of, the vertical from the posterior margin of the eye; dorsal profile almost straight; 

 ventral profile of the head sloping caudad at an angle of 45°; the body tapering; 

 snout short and pointed; mouth very narrow; gape quite short; upper jaw over- 

 lapping lower; teeth present in both jaws; eyes large, greater than maxillary. 



Caudal peduncle narrow, ribbon-like, equal to about half the total length 

 without the head; pectorals about twice the eye; origin of the anal slightly behind 

 the base of the pectorals, on a vertical from a point about the length of the snout 

 behind the head. 



Ground-color pale yellowish brown to almost yellow; origin of the anal rays, 

 the scales of the lateral line and most of the dorsal scales more or less outlined with 

 black; a narrow median dorsal streak of dark brown or black; top of head blue- 

 black; fins hyaline. 



Living fishes of this species are quite translucent, the viscera and backbone 

 being visible in outline. General color pink to light red, due to the blood showing 

 through the colorless muscle tissue. 



This species, the " Loga Loga," has no food value, being too small. The largest 

 specimen known is 200 mm., taken by Dr. Eigenmann from Rockstone, British 

 Guiana. It is known only from the interior streams of British Guiana. 



^ Rockstone 176 178 179 181 194 



Tumatumari 170 174 182 18.3 184 



