of the Island of Trinidad^ W. I. 51 



sides of this row are the villiform teeth on tlie palatine plates ; 

 two small immovable plates, which appear to be detached from 

 the larger ones, on account of the elasticity of the osseous 

 peduncles which bear them, are also covered with villiform 

 teeth. 



Lateral line running in a straight line to the caudal fin. 



Branchiostegal rays five, flat, and broad. 



Dorsal subquadrate, with the height and length nearly equal, 

 placed nearly in the middle of the body. 



Anal posterior, with the height and length nearly equal, and 

 with the margin arched, the rays increasing in length towards 

 the middle or posterior third. 



Caudal covered at the base by scales, and with a rounded 

 margin. 



Yentrals and pectorals of moderate size, and with rounded 

 margins. 



In the description of the dentition of this and of the succeed- 

 ing genus, we have followed M. Yalenciennes. 



Iflacrodon Terox, Gill. 



YER:firAcuLAR : Yarrow. 



Body moderate, compressed, with the dorsal outline straight, 

 and the abdomen arched. The head is compressed, elongated, 

 and from the snout to the opercular margin, constitutes a quar- 

 ter of the entire length, inclusive of the caudal; the eyes have 

 diameters which nearly equal a fifth of the length of the head ; 

 they are separated from each other by a space equal to seven- 

 sixths of a diameter, and are nearly as far distant from the 

 snout. The height of the body is considerably less than a sixth 

 of the entire length ; the thickness is three fifths of the height. 

 The ventrals are considerably in advance of the centre of the 



