124 MEMOIRS OF THE CARNEGIE MUSEUM. 
dorsal. Snout heavy, rather pointed, but truncate at the tip; mouth moderate, 
gape reaching about half-way to the eyes; Jaws equal, lower included on the sides. 
Caudal peduncle 4.5 to 5 in the total length; pectorals about twice the snout 
behind the eye. 
Ground color of preserved specimens stone-gray to buff; body closely pigmented 
with minute purple spots, which are more abundant dorsally; a yellowish white 
lateral streak of variable intensity and width (being almost wanting in some speci- 
mens) beginning a little ventrad of the lateral line, at a point about half the total 
length from the head and continuing well out on the caudal appendage; generally 
a blue-black spot about twice the size of the eye at the origin of the lateral line; 
head rather dark above; fins hyaline. 
Living specimens are quite translucent, so much so that the backbone and 
viscera may be seen in outline. The muscles are clear, transparent, appearing 
bright red on account of the blood contained. With the blue chromatophores and 
yellow epidermis the general color of the fish changes to orange quite readily. 
(See Color-changes.) Some specimens from Potaro Landing and others from Aruka 
and Amatuk were very much darker than the average. Since the ground-color 
was darker (a dark blue) the lateral stripe appeared more strikingly white in these 
specimens. 
S. macrurus is eaten by the natives and travellers, although it is not a market- 
fish. It has a very good flavor and rather solid meat. The species of Sternopygus 
and those of Eigenmannia are not differentiated by the natives, since the living 
fishes look very much alike; in fact Sternopygus macrurus and Higenmannia 
virescens can scarcely be separated at a glance in the field. Accordingly these 
fishes are all grouped under one name: ‘“‘Cuchillo”’ or ‘Cuchilla” in the Spanish- 
speaking countries, and ‘‘Sabre”’ in French Guiana on account of their ‘‘knife- 
like” shape. Similarly the coolies and natives of British Guiana know these 
fishes as the ‘‘Loga-Loga” or ‘“‘Laga-Laga.’”’ In Ecuador the names ‘Raton 
negro” and “Bio” are given to Sternopygus alone. The maximum size as given 
by Humboldt is about three feet. 
Habitat: Streams in open or savannah country, trenches, and ditches on 
plantations. 
Distribution: Orinoco, Guiana, Amazons, Rio San Francisco, Rio Magdalena, 
and west coast of Ecuador. 
4. Sternopygus obtusirostris Steindachner. 
Sternopygus obtusirostris STEINDACHNER, Flussf. Siidam., II, 43, pl. I, fig. 3, 1881 
(Amazon at Teffé, Lago Alexo, Manacapuru, Rio Madeira, Rio Puty); EraEn- 
MANN AND HIGENMANN, Proc. U. 8. Nat. Mus., XIV, 1891, 62; ErGENMANN, 
tepts. Princeton Univ. Exp. Patagonia, III, 1910, 450. 
Gymnotus obtusirostris EIGENMANN AND Warp, Proc. Wash. Acad. Sci., VII, 1905, 
177 (Amazons and Rio Puty); von Inprina, Os Peixes do Brazil, Part 1 A, 
286 (Rio Amazonas, curso media). 
