M U R E X (Pteronotus,) pinnatus. 



Finned Mar ex. 



Family Buccinidse. Sub-fam. Muricinee. Sw. Genus Murex. Lam. 

 Sub-genus Pteronotus. Sw. 



Sub-Generic Character. 



See PL 100. 



Specific Character. 



Shell snowy white, with three twisted varices, which are sur- 

 mounted by a thin, dilated fringe, having the margins 

 undulated ; channel curved ; outer lip crenate. 



Murex pinnatus. Swains. Dligh. Cat. App. p. 17. 

 Martini. Conch. 3 pi. in. fig. 1036—1037. {bad.) 



This highly elegant and delicate species was first described 

 by us in the Catalogue of the Bligh Collection, at the sale 

 of which a specimen produced five pounds. Latterly, 

 however, the species has become more frequent : the figures 

 are taken from a fine individual in our Museum, procured 

 fron China. The pure white of the surface is relieved by 

 a slight iredescent or pearly gloss, similar to that on the 

 scales of many fish : but which is probably concealed, in a 

 state of nature, by a thick and soft epidermis, similar to 

 that of Triton corrugatum, Lam. 



The structure of this sub-genus is further remarkable for 

 the prolongation of the basal end of the principal varcx on 

 the body whorl, which, in nearly all the species, is so 

 prominent, as to give the shell an appearance of having two 

 channels. It is remarkable that this horn-like process 

 occurs in that part of the shell which is immediately above 

 the head of the animal : so that even in this genus of 

 Mollusca we see a manifestation of that principle of the 

 natural system, by which one of the abberant types of 

 nearly all animals have crests, horns, or similar protuber- 

 ances on or near the head. 



