544 BULLION.. 



to the exotic species so called by Chemnitz, and applied 

 the appropriate name pectinata to the present shell. It 

 appears, however, that eighty plates of Miiller's work 

 were published as "Zoologiee Danicpe '' before that volume 

 of the " Conchylien Cabinet " which contains the species in 

 question ; consequently it is the species of Chemnitz, not 

 that of Midler, which must receive another appellation. 



This beautiful shell is of an uniform snow-white, very 

 thin, and semitransparent, and of an oblong-subcylindra- 

 ceous form, that is a little dilated and obliquely sub- 

 truncated below, and terminates likewise abruptly above, 

 though the upper edge of the body is rounded off. A most 

 dense array of continuous impressed dots, arranged in spiral 

 rows, though the series diverge a little at the extremities, 

 pervades the external surface, and pectinates the margin 

 of the front extremity of the aperture in perfect indivi- 

 duals. A whorl or two, separated by a rather shallow, 

 but broadly canaliculated, suture, is visible upon the crown 

 of the shell, above which latter the very blunt apex barely 

 protrudes, the spire not being elevated. The surface is 

 decidedly convex, but the shell is much compressed, the 

 depth being very inferior to the breadth. The aperture is 

 very ample, and fills from three-fifths to two-thirds of the 

 ventral area ; it is somewhat ham-shaped, narrow above, 

 though quickly dilating anteriorly, and so very bluntly 

 rounded below, where both lips recede considerably, that 

 the broad extremity seems almost truncated. The outer 

 lip is not much arcuated, and bends to the right ; it is 

 almost at a level with the apex at its junction with the 

 body, and advances and curls inwards a little above ; the 

 edtve itself is convex. The columella is sliced away, as it 

 were, so as to display the internal gyration. The pillar 

 lip is moderately incurved, and its edge seems a little 



