126 MEMOIRS OF THE CARNEGIE MUSEUM. 
SPECIES OF HIGENMANNIA. 
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 heady... ...--...---2..--+ses see wee esse cess macrops. 
aa. Maxillary about equal to the diameter of the eye; eye medium; caudal filament cylindrical, less than 
half the leneth: of the anal sci... 5 eer eee cts. serene Te eet eee ene eee virescens. 
aaa. Maxillary about twice the diameter of the eye; eye small; caudal filament less than half the length of 
the anal ye. soon evs &, 0c wo. chlo gw Gave ee tia pos Ce hea Ce TE Cae ee troscheli. 
5. Eigenmannia macrops (Boulenger). (Plate XXII, fig. 1.) 
Sternopygus macrops BouLENGER, Ann. Mag. Nat. Hist. (6), XX, 305 (Potaro 
River, British Guiana). 
Higenmannia macrops EIGENMANN AND Warp, 1905, Proc. Wash. Acad. Sci., Vol. 
VII, p. 172 (Potaro(?) River, British Guiana); ErgGENMANN, 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, Kigenmann. 
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.* 
Snout 3.2 to 3.4, interorbital about 3.3 in the head; eye equal to or a little 
ereater 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. 
‘Rockstonesnsmaen ere eee 176 178 179 181 194 
Tumatumanrie sce see 170 174 182 183 184 
