324 CHONDROPTERYGII. RAY FAMILY. 



on account of their form, and not a few of them of 

 great value in a commercial point of view. They 

 are even more strictly flat-fish than the Pleuronec- 

 tidae, but they do not exhibit that want of symmetry 

 which is so conspicuous in that family. The nos- 

 trils, mouth, and branchial apertures are on the 

 under side, and the eyes and temporal orifices on the 

 upper side of the head. The body is very much de- 

 pressed, and of a rhomboidal shape ; its great pro- 

 portional breadth being produced by the inordinate 

 expansion of the pectoral fins, which not only sur- 

 round the sides of the body, but likewise envelope 

 the head, often forming a conical projection in front 

 of it. The teeth are lozenge-shaped, forming a pave- 

 ment ; in old males the inner angle produced into a 

 sharp point directed inwards. The tail is slender, 

 usually armed with spines on the surface, and hav- 

 ing two small fins near the end, with, occasionally, a 

 rudimentary caudal. 



(Sp. 234.) R. mucronata.. Long-nosed Skate. 

 In this and some of the following species, the skin 

 is perfectly smooth, for which reason Bonaparte has 

 placed some of them in his genus Lceviraja. Mr. 

 Couch has supplied all the information we possess 

 regarding the long-nosed skate, and Mr. Yarrell has 

 given a figure of it. It is distinguished not only by 

 the great length of the nose, but also by the distance 

 between its most extreme point and the transverse 

 line of the mouth. The nose is much more produced 

 than in the following species, although that is also 

 remarkable for a like peculiarity ; and the greatest : 



