442 MEMOIRS OF THE CARNEGIE MUSEUM 



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, the former rather elongate; width of the latter 

 2.5-3.1, its depth in the occipital region 1.3-1.6 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 1.8-2.5, pectorals 1.2-1.5 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 out- 

 lined with brown; ventral parts lighter; a series of oblique blackish brown stripes, 

 alternating 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. 



A specimen, No. 2972, from Santarem, 190 mm., with head 7.5, snout 3, and 

 A. 175, probably belongs here. 



Order SYMBRANCHII. 74 

 Family XL SYMBRANCHID^. 



Symbranchus Bloch. 

 Synbranchus Bloch, Ausl. Fische, IX, 1795, 87 (marmoratus). 

 Unibranchapertura Lacepede, Hist. Nat. Poiss., V, 1803, 658 (marmoratus). 

 Ophisternon McClelland, Calcutta Journ. Nat. Hist., V, 1845, 197 (bengalensis). 

 Tetrabranchus Bleeker, Nat. Tijdschr. Ned. Ind., II, 1851,69 (microphthalmus) . 



Type, Synbranchus marmoratus Bloch. 



Eel-shaped, naked ; abdomen much longer than the tail ; gill-membranes united, 

 leaving a single small median opening on the ventral surface; eye small, about 2 

 in the snout. 



"It is very probable that the ordinary eel, Anguilla chrysypa, occasionally occurs in the fresh waters 

 of Guiana, and Mutter and Troschel remark that Lycodontis occllatus (Agassiz) is sometimes taken in the plan- 

 tation drains and reaches a length of three to four feet. The specimen in the Berlin Museum is 380 mm. long. 



