noun, plural pro·tho·rax·es, pro·tho·ra·ces [proh-thawr-uh-seez, -thohr-] /proʊˈθɔr əˌsiz, -ˈθoʊr-/.
Examples from the Web for prothorax
Principal sulcus: in Orthoptera, a transverse impression of the prothorax, at or behind the middle.
Prothorax two-thirds wider than long, sides parallel in basal half, convergent anteriorly.
Prozona: in Orthoptera, the upper or dorsal surface of prothorax in front of the principal sulcus.
Microthorax: a supposed thoracic ring between the head and prothorax.
There is a long neutral interval, that of the prothorax, into which it is quite useless to drive the sting.More Hunting Wasps|J. Henri Fabre