Tunica propria: a layer of epithelial cells and connective tissue lining the interior of the hind gut: the outer layer of the silk glands: a covering or investing membrane.

Tunicate: composed of concentric layers, enveloping one another: said of antennae when each successive joint is buried in the preceding funnel-shaped one.

Turbinate: top-shaped; nearly conical: differs from pyriform in being shorter and more suddenly attenuated at base: applied to an eye = pillared eye; q.v.

Turgid: swollen.

Turritus: towering: a surface rising cone-like.

Tylo: = tylus; q.v.

Tylus: the anterior central lobe of the head in Hemiptera.

Tympana: the ears in Orthoptera.

Tympanal: applied to organs covered with a tympanum or stretched membrane supposed to function as ears.

Tympanic spiracle: in Diptera, the thoracic spiracle at base of wing.