Opoterodonta

Opoterodonta \Opoterodonta\, prop. n. pl.
   An older division of the suborder {Ophidia} of serpents; it
   includes those snakes in which the mouth is not dilatable.
   [PJC]
    

Ophidia \O*phid"i*a\, prop. n. pl. [NL., fr. Gr. ?, dim. of
   'o`fis a snake.] (Zool.)
   The suborder of reptiles which includes the serpents; called
   also {{Serpentes}}.
   [1913 Webster +PJC]

   Note: The most important divisions are: the {Solenoglypha},
         having erectile perforated fangs, as the rattlesnake;
         the {Proteroglypha}, or elapine serpents, having
         permanently erect fang, as the cobra; the {Asinea}, or
         colubrine serpents, which are destitute of fangs; and
         the {Opoterodonta}, or {Epanodonta}, blindworms, in
         which the mouth is not dilatable.
         [1913 Webster]