116 MEMOIRS OF THE CARNEGIE MUSEUM. 
Vol. 55, 508, 1897 (Waini River, Brit. Guiana); von InEerRING, Revista Mus. 
Paulista, 286, 1907 (Amazonia, Guyana); ErGENMANN, Repts. Princeton 
Univ. Exp. Patagonia, III, 1910, 449. 
Gymnotus regius DELLE CutasE, N. Ann. Se. Nat. Bologna, VIII, 1847. 
1302 C. M., three, 650 to 825 mm. Tumatumari, Brit. Guiana, Kigenmann. 
1754 C. M., 126351. U. M., three, 190-580 mm. Creek below Potaro Landing, 
Brit. Guiana, Shideler. - 
1755 C. M., one, 460 mm. Pacopoo Pan, Brit. Guiana, Grant. 
5100 I. U. M., one, 330 mm. Brazil. 
One specimen, Hubabu Creek, Brit. Guiana, Oct. 1, 1910, Ellis. 
Head 8 to 9.2; depth 14.5 to 16 in the length to the end of the anal; anal rays 
357, 362, 324, in three specimens. Snout about 3.5, interorbital a little less, in 
the head; eye 5 to 5.2 in the snout, and 15 or 16 in the head. 
Body cylindrical, elongate, naked; head depressed; width of the head about 
equal to, and depth a little less than, the greatest depth of the body; anus a little 
more than the length of the snout behind the vertical from the eye in front of the 
pectorals; ventral and dorsal profile almost straight. 
Snout heavy and broad; mouth large; gape moderately long, but not quite 
reaching to below the eye; lower jaw protruding; teeth small, conical, a single 
row in each jaw; eyes small, without free orbital margin. 
Origin of the anal about the length of the head behind the pectorals; anal fin 
of uniform width and continuing around the end of the tail so as to form a false 
caudal; pectorals small, fan-shaped, 2.8 to 3.5 in the head. 
Ground-color in life olive-green or dark blue to almost black; ventral parts 
of head and pectoral region light yellow to orange-red; fins dark, fringed with 
hyaline. 
This species is occasionally used for food by the Indians. It is rather gener- 
ally avoided by the natives on account of the powerful electric shock it can give, 
that of an eel five feet long being sufficient to knock a man down. 
The maximum size for this species, recorded from British Guiana, is seven 
feet four inches. This specimen was taken by Mr. J. J. Quelch from the Waini 
River, British Guiana, in 1897, and the skin is now in the Georgetown Museum. 
Habitat: Pools and deeply shaded places in small streams and creeks. 
Distribution: Orinoco, Guianas, and the Lower and Middle Amazon Systems. 
II. Gymnorus Linnezeus. 
Gymnotus LiInnmus, Syst. Nat., ed. X, 246, 1758; ed. XII, 1, 427, 1766. 
Type, Gymnotus carapo Linnzeus. 
Size moderate, not exceeding 600 mm. in length. No frontal fontanel; no 
caudal fin; a caudal filament, no electrical organ; cylindrical anteriorly, somewhat 
compressed posteriorly; head large and depressed, the top quite flat; gape not 
reaching the eyes; lower jaw protruding; teeth small, conical, in one row (which 
