The skin of Triclads is full of minute rods or rhabdites, which are shot out in great numbers when the animal is irritated, and doubtless serve an offensive purpose. The Terricola possess two kinds of these: (1) needle-like rods; and (2) in _Bipalium kewense_, flagellated structures, bent into a V-form and with a slender thread attached to one end (Shipley). In _Geoplana coerulea_ these bent rods furnish the blue colour of the ventral surface. The rhabdites arise in all Triclads in cells below the basement-membrane, which they are said to traverse in order to reach the epidermis, thus differing in origin, and also in structure, from the rods of Polyclads. FOOD.—Triclads are largely if not wholly carnivorous animals, feeding upon Annelids, Crustacea, Insects, Insect-larvae, and Molluscs. The mouth is usually mid-ventral or behind the middle of the body, but in the anomalous _Leimacopsis terricola_ Schm. from the Andes[54] and in _Dolichoplana_ it is near the anterior end. The pharynx (Figs. 17, 18, _ph_) is cylindrical or bell-shaped, exceedingly dilatable and abundantly supplied with glands and nervous tissue. It opens into the three main intestinal branches, one of which runs in the median plane forwards, the others backwards right and left, enclosing a space in which the genital ducts lie (Figs. 14, A, 17). The fresh-water Planarians prey upon Oligochaeta, Hydrophilidae (aquatic beetles), and the commoner pond-snails. _Bipalium kewense_ pursues earthworms, seizes the upper surface of the anterior end by the glutinous secretion of its ventral surface, and then proceeds to envelop part or the whole of the worm within its pharynx, which is stretched as a thin skin over the body of its struggling prey (Lehnert). The tissues of the latter pass into the intestine of the Planarian, and distend it greatly. After such a meal, which lasts from one to five hours, a _Bipalium_ may remain for three months without seeking food. _Geobia subterranea_, a white eyeless form from Brazil, pursues earthworms (_Lumbricus corethrurus_) in their burrows, and has been seen by Fritz Müller sucking the blood out of a young {38}worm.[55] _Geoplana typhlops_, a Tasmanian species, is also blind, and pursues worms, as does _G. triangulata_ (Dendy). In Trinidad, von Kennel[56] observed that land-snails (Subulinae) were the food of certain Land Planarians, the name of which, however, he does not state. The pharynx was employed to suck out the soft parts of the snail even from the upper whorls of the shell.