Notice of a New Ganoid Fish. 



275 



respect almost serpent-like in its general aspect, the ab- 

 dominal region of the body being very long. Its bony scales 

 are hard and sculptured, and correspond to Polypierus in 

 their general arrangement. 



The Head is small and depressed towards the front, which 

 is narrow. It becomes broader behind the eyes, where it 

 bulges outwards laterally, becoming rather contracted again 

 at the back part of the operculum. The upper parts of the 

 head are covered by a series of bony plates, somewhat irre- 

 gular in shape, which correspond generally to one another 

 on the opposite sides of the head, and bear a close resem- 

 blance in their arrangement to those of the Genus Polyp- 

 terus. Below the range of small spiracular plates, which 

 run along the sides and back part of the head, there is a 

 somewhat triangularly-shaped operculum, with an irregularly 

 oval-shaped preoperculum in front of it. There are, how 

 ever, no small plates below the preoperculum, as in Polyp- 

 terus. On each side of the mesian line below, you have a 

 large-sized bony branchial or jugular plate, rounded behind 

 and pointed in front, as in Polypterus, which covers most of 

 the space between the rami of the lower jaw, at least towards 

 its anterior extremity. 



A series of small perforations, or openings of mucous 

 ducts, ten in number, surround the orbit at some little 

 distance, running in an oval form around it ; and beyond 

 these are other sixteen openings, running in a curved direc- 

 tion from above downwards, along the margins of the 

 smaller intermediate range of plates already described ; 

 others also open between the operculum and preoperculum. 



The Fins are small. The dorsal flnlets are very small, 

 and apart from each other, and they begin on the back, 

 at a great proportional distance from the snout of the 

 fish. To show their difference in this respect from the 

 species of Polypterus, I may state, that at the commence- 

 ment of the dorsal flnlets, the body of the fish measures 

 about half an inch in depth, and is nearly 4 J inches in 

 length, from the same point to the extremity of the snout ; 

 so that the distance from the snout to the commencement 

 of the dorsal fins is about 9 times the depth of the body. 



VOL. III. 2 N 



