cephalostyle

from The Collaborative International Dictionary of English v.0.48

Cephalostyle \Ceph"a*lo*style\ (s[e^]f"[.a]*l[-o]*st[imac]l), n.
   [Cephalo- + Gr. sty^los a pillar.] (Anat.)
   The anterior end of the notochord and its bony sheath in the
   base of cartilaginous crania.
   [1913 Webster]