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Tripartite — divided into three parts. 

 Turbinate — top-shaped. 



Umbilicus — the external opening of the hollow axis of ;i 



loose coiled shell. 

 Umbo — the area about and including the beak in Pelecypods 



and Brachiopods. 



Varix — a row of spines, a ridge or other mark, denoting the 

 former position of the lip on the shell of a gastropod 

 (PL varices). 



Ventral — pertaining to the lower side, or venter. 



Yentricose — strongly swollen, or bulging. 



Vesicular — bearing vesicles, or hollow cavities. 



Vestibular area — the area surrounding the cell apertures of 

 some Brvozoa; often depressed. 



Whorl — a single volution of a coiled shell. 

 Wing — the posterior larger expansion along the hinge line 

 of a Pelecypod. 



Zoarium — the aggregates of the polypites of a Bryozoan 



colony. 

 Zocecium — the Bryozoan cell. 

 Zooid — one of the "persons" or individuals of a zoarium. 



