The Collaborative International Dictionary of English v.0.48:

Opisthoglypha \O*pis`tho*glyph"a\, n. pl. [NL., from Gr.
   'o`pisqen behind + ? to carve.] (Zool.)
   A division of serpents which have some of the posterior
   maxillary teeth grooved for fangs.
   [1913 Webster]