(kot) [coitus, a tunic]. A cover or mem- brane covering a part or substance. C, Buffy, the upper fibrinous layer of the clot of coagulated blood, characterized by its pale color, due to absence of red corpuscles. C, Internal Elastic. See Henle's Fenestrated Membrane. C, Internal Fibrous. See C, Subepithelial. C, Middle, the tunica media. C, Subepithelial, the middle layer of the intima, composed of fusiform and stellate cells and finely granular substances with lon- gitudinal and transverse fibrils. Syn., In- nermost longitudinal fibrous coat; Inter- mediary layer; Internal fibrous coat; Striated layer of the internal coat. C, Uveal, the uvea. C, Vaginal. 1. The fibrous capsule of the eyeball. 2. See Tunica vaginalis.