134 



of a new genus, for which he proposed the name Bankivia. To the great 

 loss of Conchology that important work remains still incomplete, the text 

 never reached so far as to include the present genus, and I am not aware 

 that any publicity has yet been given to it. 



The shell of Bankivia, it will be observed, has few characters in common 

 with Elenchiis ; it has apparently no epidermis, and is of the same por- 

 cellanous structure as PhasianeMa, sometimes banded with deep red and 

 purple, sometimes, as in the variety selected for illustration, painted with 

 fine zigzag lines. The columella presents, however, the most important 

 generic feature, in being thickly rolled and twisted, truncated at its junc- 

 tion with the lip, which is thin and not reflected. The interior of the shell 

 is faintly iridescent. 



Figure. 



Bankivia purpurascens. PI. 2. Fig. 61. Shell, showing the truncated 

 columella. 



Genus 5. LITTORINA, Ferussac. 



Animal ; disk small, thin at the edge and nearly circular, almost 

 concealed by the shell, furnished behind with a horny blackish 

 operculum ; head somewhat thickened, prolonged into a conical 

 snout, which is transversely wrinkled and cleft at the extremity 

 by the mouth ; tentacles conical, broad at the base, at the outer 

 sides of which are situated the eyes. 



Shell ; turbinated, not pearly, small, mostly rather solid, columella 

 somewhat flattened, arched ; aperture rotundately ovate, margins 

 disjoined, lip sharp, sometimes slightly expanded. 



The common Periwinkle of our shores, LiUorina vulgaris, may be 

 referred to as a familiar type of this very natural group, including a multi- 

 tude of species of which many remain to be described. Lamarck con- 

 founded some with the Turbines, some with the PhasianeMa, and even 

 De Ferussac, after founding the genus, left it not a little confused through 

 the introduction of several Paludina, which have for the most part thinner 

 shells, and are not of the same marine habits. 



The general aspect and composition of the shells of the Littorina seem 

 to indicate sufficiently that they belong to an animal dissimilar from 

 PhasianeMa, and so it proves to be; it is comparatively smaller, with a 



