24 NOMENCLATURE. 



Venter seu Corpus. Belly or Body; the 

 lowest whorl, the last circumvolution of the 

 shell, which is the most tumid. 



Vertex. Vertex; in the Patella signifies the 

 supereminent point of the shell. 



submarginalis. Submarginal ; placed near the 

 posterior margin. 



Umbilicus. Umbilicus; a hole in the base of 

 the columella visible underneath. 



perforatus. Perforate ; having a hollow duct or 

 opening through the centre to the very 

 apex. 



subobtectus seu Rima umbilkalis. Umbilical 

 cleft; where the lip is reflected over the 

 hollow, and only the margin of the opening- 

 is apparent. 



Margo columnaris. Columnar Margin ; when the 

 margin of the columella forms the interior 

 wall of the aperture. 



