124 MEMOIRS OP 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. macnirus 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 bj^ the natives, since the living 

 fishes look very much alike; in fact Sternopygus macrurus and Eigenmannia 

 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, pi. II, fig. 3, 1881 

 (Amazon at Teffe, Lago Alexo, Manacapuru, Rio Madeira, Rio Puty) ; Eigen- 



MANN AND ElGENMANN, PrOC. U. S. Nat. Mus., XIV, 1891, 62; ElGENMANN, 



Repts. Princeton Univ. Exp. Patagonia, III, 1910, 450. 

 Gymnotus obtusirostris Eigenmann and Ward, Proc. Wash. Acad. Sci., VII, 1905, 

 177 (Amazons and Rio Puty); von Ihering, Os Peixes do Brazil, Part 1 A, 

 286 (Rio Amazonas, cur so media). 



