342 NATICIDiE. 



The shell has a subglobose form that is rather longer 

 than broad, and is about equally narrowed at each extre- 

 mity. It is moderately strong, quite smooth, and covered 

 with a rather dull pale ash-coloured or yellowish horn- 

 coloured epidermis, beneath which it is pure white. The 

 body is very large, simply ventricose, not at all flattened 

 in the middle, and is well rounded both above and below, 

 yet rather more gradually so anteriorly. The short blunt 

 spire is somewhat dome-shaped, and is usually eroded at 

 the apex ; it only fills a fifth of the dorsal length, and is 

 composed of three or four very short quickly tapering com- 

 pressed, yet convex (not scalar) volutions, that are divided 

 by a fine but profound suture, and are of rather slow longi- 

 tudinal increase. The aperture, whose basal recedence is 

 rather less than is usual in the Nathet^ is of an uniform 

 polished Avhite, of a suboval figure, and rather large, 

 since it occupies at least three-fifths of the ventral length, 

 and measures in a line with the umbilicus quite one-half 

 of the transverse diameter : the throat is quite smooth. 

 The outer lip is thin, sharp, and simple ; it projects at right 

 angles to the body, and its sweep is almost a semicircle. 

 The enamel of the inner lip, though not broadly, is rather 

 thickly spread ; the pillar lip is wide, and its simplicity is 

 not disturbed by any callous projection or indentation. 

 The umbilical perforation is so narrow as to be scarcely 

 more than a linear chink. Seven lines long, and six broad 

 are the dimensions of the individual specimen measured by 

 us, but we believe that this is not the extreme size that 

 the species attains to. 



This very rare species (the animal of which is a deside- 

 ratum) was taken first by Mr. Bean off the Yorkshire coast. 

 Mr. King has dredged it alive in fifty fathoms on the coast 

 of Northumberland, where it has also been taken by Mr. 



