Most species have massive shells with three or four prominent columellar plicae. The shell is finely flexuously longitudinally plicate with about twenty plicae. The armor-like lorica consists of a protective external shell or case of encircling plicae. The corolla has folds called plicae between the lobes. The shell of this species is massive, with three or four prominent columellar plicae. The inner lip is calloused, showing transverse plicae. The plicae fimbriatae move freely over a limited range. The shell is longitudinally plicate, with the plicae more prominent at the base. The plicae circulares are the best developed in the jejunum. The plicae from the host brachiopod will then appear within the shell of the craniata. Folds or plicae are named by their position in the aperture, as follows. Normal "plicae circularis" are variable in appearance and often not seen on normal VCUGs.