Mesostethidium: = meso-thorax: q.v.
Mesostethium: the middle piece of the underside of meta-thorax, between the middle and hind legs.
Mesostigma: in Odonata, the spiracles of second thoracic segment.
Mesosulcus: a central longitudinal furrow of mesosternum in Hymenoptera.
Mesotarsus: the tarsus of the middle leg.
Mesothoracotheca: the pupal covering of the meso-thorax.
Mesothorax: the second or middle thoracic ring; bears the middle legs and the anterior wings.
Mesotergum: = mesonotum; q.v.
Meta-: posterior: used as a prefix to designate the third thoracic ring and its parts.
Metablastic: relating to the ecto- or meta-blast or ectoderm.