mesophragma

from The Century Dictionary.

• noun In entomology, a transverse internal partition, descending from the anterior border of the metathorax above, between the mesothorax and the metathorax, and serving for the attachment of muscles. It probably corresponds to the metapræscutum; it is often absent.
• noun In Crustacea, that process of an endosternite (or intersternal apodeme) which is directed inward to unite with its fellow and form an arch over the sternal canal. See sternal canal, under sternal.