112 THE ELEMENTS 



Fig.l2th.~CONUS VARIA. Rub- 

 bed through on one side to show the 

 internal structure of the shell. 



D spire, F body, M MM pillar or 

 columella. 



PLATE III. 



Fig. 3d.— TROCHUS UMBILI- 

 CATUS. Shell conico-convex, flat- 

 tisb, rounded at the top ; apex depres- 

 sed, volutions five, slightly emarginate, 

 defined by a fine line ; spirally striate, 

 rather whitish, with zigzag lines of 

 purple ; aperture compressed and an- 

 gulated ; with a large umbilicus which 

 extends to the apex. Found on the 

 Northumberland and Yorkshire coasts. 



Linn. Trans, vol. viii. page 153. 



C Aperture, U umbilicus. 



Fig 2d.— HELIX NEMORALIS. 

 Shell imperforate sub-globose, thin 



