30 ANNALS OF SCOTTISH NATURAL HISTORY 



Fishes," vol ii. PL CLXXI. Fig. 2 ; and the extraordinary mon- 

 strosity in the same species figured in the third edition of 

 Yarrell's "British Fishes," vol. ii. p. 584, seems to be of the 

 same nature, though in addition the pectoral fins are deformed 

 in their shape. This condition in a Ray offers a certain 

 amount of analogy to those well-known instances of Turbots 

 and Flounders, in which the anterior extremity of the dorsal 



fin also projects forward as a free pointed process instead of 

 being tied down to the top of the head. In these Pleuro- 

 nectids, however, this stateof the dorsal fin is alwaysdetermined 

 by an arrestment, to a greater or lesser degree, of the move- 

 ment of the upper eye from the blind to the ocular side of 

 the head, but it is difficult to conceive of any cause which 

 might underly the non-adherence of the extremities of the 

 pectorals in these abnormal Thornbacks. 



