(microbiology, planktology) Of or pertaining to the epitheca, the upper half of the shell of certain types of plankton.
1919, G.M. Ehlers, New Species of Tetracoralla in The American journal of science, Vol. XLVIII:The epithecal covering of the outer is annulated by low ridges and shallow grooves...Fine, close-set, concentric lines, probably representing lines of growth, are obscurely shown on a few of the better preserved portions of the epithecal surface.
