hyposternum

from The Collaborative International Dictionary of English v.0.48

Hypoplastron \Hy`po*plas"tron\, n.; pl. {Hypoplastra}. [Pref.
   hypo- + plastron.] (Anat.)
   The third lateral plate in the plastron of turtles; -- called
   also {hyposternum}.
   [1913 Webster]

from The Collaborative International Dictionary of English v.0.48

Hyposternum \Hy`po*ster"num\, n.; pl. L. {Hyposterna}, E.
   {Hyposternums}. [Pref. hypo- + sternum.] (Anat.)
   See {Hypoplastron}. Hypostome

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