Cinclides: Perforations of the column wall, and can be of two kinds. In one they constitute actual perforations, being minute channels leading from the coelenteron to the exterior; they penetrate the mesoglea and are lined by epithelium. In the other type, no perforation of the whole wall exists, but the mesoglea is either much reduced or actually interrupted so that the cellular layers come into contact, and an organized “soft spot” is thus formed which will rupture on the exertion of sufficient pressure from within. The region immediately surrounding the perforation may form a thin diaphragm of reduced mesoglea, sometimes bearing circularly arranged muscle-fibers which constitute a minute sphincter. The main function of a cinclide is to provide a pore through with water and acontia can exit. It should be noted that acontia and cinclides can occur independently from one another, and either one, the other or both may occur in certain species. (Adapted from Stephenson, 1928; p. 19).