500 PISHES. 



sion is of a lighter and more clear blueish colour than the upper 

 or back part, and seems to swell out somewhat on each side, from 

 the depression of the lateral lines ; but towards the lower or under 

 part, is again contracted, or sharpened into the third part or carina. 

 This carina or keel is very distinguishable from the other two divi- 

 sions by its thinness, its apparent laxness, and by the reticulated 

 skin of a more grey or light colour, with which it is covered. 

 When the animal swims gently in pretty deep water, the rhom- 

 boidal reticulations of the skin of this carina are very discernible ; 

 but when the water is shallow, or the depth of the carina is con- 

 tracted, these reticulations appear like many irregular longitudinal 

 plicae. The carina begins about six or seven inches below the base 

 of the head, and gradually widening or deepening as it goes along, 

 reaches down to the tail, where it is thinnest. It seems to be of a 

 Strong muscular nature. Where it first takes its rise from the 

 body of the fish, it seems to be about one inch, or one inch and a 

 half thick, and is gradually sharpened to a thin edge, where the 

 fourth or last is situated j viz. a long, deep, soft, wavy fin, which 

 takes its rise about three or four inches at most below the head, 

 runs down along the sharp edge of the carina to the extremity of 

 the tail. When it first rises it is not deep, but gradually deepens 

 or widens as it approaches the tail. It is of a very pliable soft 

 con c istence, and seems rather longer than the body. The situation 

 of the vent of this fish is very singular, being placed underneath, 

 and being about an inch more forward than the pectoral fins, and 

 consequently considerably nearer the rostrum. There are two 

 pectoral (if I may call them so) fins, placed one on each side, just 

 behind the head, over the foramina spiratoria, which are small, and 

 generally covered with a lax skin, situated in the axillae of these 

 fins. These fins are small for the size of the fish, being scarcely an 

 inch in length, and of a very thin, delicate consistence, and orbi- 

 cular shape, They seem to be chiefly useful in supporting and 

 raising the head of the fish when he wants to breathe, which he does 

 every four or five minutes, by raising his mouth out of the water. 

 This shews that he has lungs and is amphibious, and the foramina 

 spiratoria seem to indicate his having branchiae likewise*; but this 

 I only offer as a conjecture, not being certain of the fact. I must 



* This idea has since been proved erroneous ; the gymnote is not strictly 

 amphibious, any more than the eel. 



