• A marine univalve shell of the genus Bulla and allied genera, belonging to the Tectibranchiata.
any of various marine snails of the order Cephalaspidea (subclass Opisthobranchia of the class Gastropoda). It characteristically has a thin, ... [1 related articles]
Bub'ble shell` (Zoology) A marine univalve shell of the genus Bulla and allied genera, belonging to the Tectibranchiata. 
[n] - marine gastropod mollusk having a very small thin shell
noun marine gastropod mollusk having a very small thin shell