86 



MR W. TURNER AND DR H. S. WILSON ON THE 



markings on its outer surface, evidently the scars which indicated the former at- 

 tachment either of the same, or other parasites. A similar appearance was described 

 and figured by Grant in his specimen.* It will thus be seen that there are con- 

 siderable differences in the mode of attachment of the L. elongata and Dahnanni. 

 These differences are doubtless due to the var^^ing nature of the localities in 

 which they are met with. The L. elongata, being adherent to a fiat surface, has 

 connected to the ends of its arms a sucker-like disc ; whilst the Dalmanni, being 

 to some extent buried in the substance of the skate, has the clasper-like termina- 

 tions of its arms attached to a transverse bar, which is lodged in a special cavity. 

 The comparison which we have been enabled to make between the L. elongata 

 and Dalmanni has convinced us that the differences existing between them are 

 so great, that the latter animal ought no longer to be included in the genus in 

 which it is at present placed. The mode of termination of the arms at their dis- 

 tal ends presents such striking peculiarities, that, conjoined with the elongated 

 head, the flattened, inversely heart-shaped abdomen, and the existence of poste- 

 rior abdominal appendages, we consider it ought to constitute a new genus. 



* Brewster's Edin. Journal of Science, 1827, p. 150. 



