Pŏl'y-thăl'a-moŭs, a.

adjective

a. [Gr. πολύς, many, and θάλαμος, a chamber; Fr. polythalame.] Many-chambered;—applied to cephalopods having multilocular shells.

Two views of a polythalamous shell, showing its coiled form and internal chambers.
Polythalamous Shell.