apodeme

from WordNet (r) 3.0 (2006)

apodeme
    n 1: ridge-like ingrowth of the exoskeleton of an arthropod that
         supports internal organs and provides attachment points for
         muscles

from The Collaborative International Dictionary of English v.0.48

Apodeme \Ap"o*deme\, n. [Pref. apo- + Gr. ? body.] (Zool.)
   One of the processes of the shell which project inwards and
   unite with one another, in the thorax of many Crustacea.
   [1913 Webster]