The inner surface of their cup-shaped mouth is armed with pointed teeth, with which they perforate the integuments of the fish attacked, scraping off particles of the flesh and sucking the blood.
(C original; the rest after von Koch.) aporose corals, the only communication between the cavity of the edge-zone and the general cavity of the zooid is by way of the lip of the calicle; in the latter, or perforate corals, the theca is permeated by numerous branching and anastomosing canals lined by endoderm, which place the cavity of the edge-zone in communication with the general cavity of the zooid.
Of endophytes a distinction must be made between those which occupy the cell-wall only and those which perforate the cells, bringing about their destruction.
The septa of modern perforate corals are shown to have a structure nearly identical with that of the secondary forms, but the trabeculae and their nodes are only apparent on microscopical examination.
The blastopore, bl, has The extent of the shell and closed; the anus will subcommencing upgrowth of the sequently perforate the cormantle-skirt is indicated by responding area.