NILOTIC POLYPTERUS. 123 



closely affixed to the skin, so that it may be con- 

 sidered as in some degree a mailed fish : the pecto- 

 ral and ventral fins, but particularly the former, 

 are attached by a sort of strong and scaly base or 

 cubit, allowing the same kind of motion as in those 

 of the genus Lopius among the cartilaginous fishes : 

 the pectoral fins are placed immediately beyond 

 the head ; the ventral at a vast distance beyond it, 

 the abdomen in this fish being of a very unusual 

 length: the anal fin is seated at some distance 

 beyond the ventral, very near the tail, and is of an 

 ovate, but slightly pointed shape : the tail, which is 

 rather small and short for the size of the animal, is of 

 a rounded or ovate form, and consists only of soft, 

 strait, articulated rays, so disposed in the mem- 

 brane as to allow but little freedom of motion in 

 this part : at a small distance beyond the head, 

 along the whole length of the back, runs a con- 

 tinued series of small dorsal fins, to the number of 

 sixteen, seventeen, or eighteen, the number vary- 

 ing slightly in different individuals : each of these 

 fins is of an ovate shape, upright, or but very 

 slightly inclining backwards, and is furnished with 

 a very strong spine at its base or origin, while the 

 remaining part consists of four or five soft and 

 branched rays, connected by their uniting mem- 

 brane : the first or spiny ray, at about two thirds 

 of its height from the base, sends off a small second- 

 ary point or spine : the lateral line commences at 

 a small distance from the gill-covers, from which it 

 slightly descends for a small space, and then runs 

 strait to the tail : the eyes are small and round : 



