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NOMENCLATUllE. 
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, 
submar ginalis. 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. 
subohtectus seu Rima umbilicalis. 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. 
