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.
A large number of corals, both aporose and perforate, are colonial.
In order to measure the pH directly; the kit includes a plastic auger to perforate the ground.
In favour of seeing in the lateral trunks and their branches a vascular system, is the contractility of the former, and the fact of the intrusion of the latter into the epidermis, matched among the Oligochaeta, where undoubted blood capillaries perforate the epidermis.
These often have the form of prisms of calcite surrounded by a cuti cular meshwork; the whole is nourished and kept alive by processes, which in Crania are branched; these perforate the shell and permit the access of the coelomic fluid throughout its substance.