154 MEMOIRS OF THE CARNEGIE MUSEUM. 
minute yellowish dots; lips, the openings of the mucous canals in mid-dorsal region, 
the anus, and a small spot at origin of caudal, yellowish; fins hyaline. 
Distribution: Essequibo basin, British Guiana. 
25. Porotergus gimbeli sp. nov.’ (Plate XXIII, fig. 3.) 
Porotergus gimbeli Exuis, in Eigenmann, Freshwater Fishes of British Guiana. 
Mem. Carnegie Mus., Vol. V, 1912, 441. 
3197 C. M., type, 200 mm. Parad, Jan. 22, 1910, Haseman. 
3198 C. M., cotypes, two, 170-240 mm. Para, Jan. 22, 1910, Haseman. 
Cotype, one. Hubabu Creek, B. G., Oct. 1, 1910, Ellis. 
Head 8.5 to 10.25; greatest depth of the body 8.25 to 9 in the length to the 
base of the caudal; anal rays, type, 175; cotypes, 178, 167, 180. 
Snout 3 to 3.6, interorbital 4 to 5 in the head; eye 3 to 3.5 in the snout, 2 to 2.8 
in the interorbital and 11 to 14 in the head; lateral line prominent, extending out 
on the caudal. Snout rather short and blunt; mouth moderately large; jaws equal 
when closed; the lower included; teeth small, conical and few in each jaw; eyes 
small. 
Body and head compressed, body rather elongate; width of the head 2.5 to 3.1, 
depth of the head in the occipital region 1.3 to 1.6 in the greatest depth of the 
body; anus on the vertical from the eye; scales moderately large and prominent; 
a mid-dorsal band extending to the end of the dorsal filament with numerous 
mucous pores and without scales; dorsal profile very weakly convex or almost 
straight; ventral profile somewhat convex. 
Caudal fin 1.8 to 2.5, pectorals 1.2 to 1.5 in the head; origin of the anal the 
diameter of the eye or a little more in front of the vertical from the gill-opening; 
scales extending well out on the caudal. 
Ground-color rather light yellowish brown; dorsal portions, especially the 
naked dorsal band, overlaid with dark brown; most of the scales somewhat outlined 
with brown; ventral parts lighter; a series of oblique blackish brown stripes alter- 
nating with the anal rays extending dorsad from the edge of the anal base about 
half way to the lateral line; mouths of the mucous pores and the under parts of 
the head a clear, pale yellow or buff; anal hyaline; pectorals hyaline to dusky, the 
first two or three rays usually distinctly brown; caudal base whitish, the scaled 
portion of the caudal almost black, the outer margin hyaline. 
Distribution: Lower Amazon and British Guiana. 
A specimen, No. 2972, from Santarem, 190 mm., with head 7.5, snout 3; A. 
175, probably belongs here. 
9 Named for Mr. Jake Gimbel, whose generosity made the Gimbel Expedition to British Guiana possible. 
