Ventricose shell

from The Collaborative International Dictionary of English v.0.48

Ventricose \Ven"tri*cose`\, Ventricous \Ven"tri*cous\, a. [NL.
   ventricosus, fr. L. venter belly.] (Nat. Hist.)
   Swelling out on one side or unequally; bellied; ventricular;
   as, a ventricose corolla.
   [1913 Webster]

   {Ventricose shell}. (Zool.)
   (a) A spiral shell having the body whorls rounded or swollen
       in the middle.
   (b) A bivalve shell in which the valves are strongly convex.
       [1913 Webster]