A NEW GENUS OF GANOID FISH. 463 



the operculum, becoming much broader below, to join the back part of the jugular 

 plates. (Plate XXXI. fig. 5.) 



The branchiostegal membrane, between the rami of the lower jaw, is almost 

 completely occupied by a pair of large flattened plates or rays — the jugular jilates, 

 as they have been named — the form of each being somewhat like a scalene 

 triangle, with its acute point in front, and its longest side next the ramus 

 of the jaw, the second lying parallel to the corresponding side of the other jugular 

 plate, and the third or shortest and posterior side being somewhat rounded in its 

 outline. 



All the plates of the head, as well as the jugular plates, are sculptured, show- 

 ing slight projections with rounded outlines, on their surface, which generally to- 

 wards the margins of the plates assume an arrangement of concentric lines, and 

 these lines commonly enclose a space in the centre, or towards one extremity of 

 the plate, which is filled up with shorter and more irregularly arranged pro- 

 jections. 



The Mouth is large. Its opening extends horizontally backwards beyond the 

 back part of the orbit. The jaws are nearly equal in length, the upper project- 

 ing very slightly beyond the lower. The lips are full, and expand in a free mem- 

 brane, from behind the nasal cirri, which becomes narrower towards the angle of 

 the mouth; and again expands along the sides of the lower jaw. A series of 

 strong, conical, and pointed teeth, sloping slightly backwards, extends along the 

 edges of both upper and lower jaws ; and immediately within this row, there is in 

 the upper jaw a smooth furrow or groove, which seems to receive the teeth of the 

 lower jaw when the mouth is closed. Beyond this groove in the upper jaw is a 

 patch of villous-like teeth, which is broadest anteriorly {-£$ of an inch), and crescentic 

 in shape, the horns projecting backwards; it covers the inner portion of the supe- 

 rior maxillary bones, continuing on to the palatines, the toothed surfaces becom- 

 ing granular in character. The internal pterygoid plates, and the vomer in the 

 centre of the roof of the mouth, are also all covered with granular teeth. Within 

 the lower jaw anteriorly is a crescentic patch of granular teeth, which also 

 measures -£$ of an inch across in front, and extends backwards in a line of 

 teeth along the inside of the rami of the jaw ; between this accessory group of 

 teeth in front, there also runs a fainter smooth line or furrow, somewhat similar 

 to that of the upper jaw. 



The Tongue is full and rounded, and covered with papillae, a deep fold or 

 notch, on each side, partially divides it into two portions ; and its base is covered 

 with a patch of granular teeth. 



Body. — The body is much elongated, its depth being about ^ 4 part of the total 

 length of the fish ; anguiform (cylindrical from behind the pectoral fins, to about 

 the middle of its length a little behind the commencement of the dorsal finlets ; 

 it then becomes gradually more compressed in character (laterally), but remains 



