They are stated to be extremely thirsty animals, and have been observed drinking from the dewdrops on herbage. It is probably on this account that they are sometimes seen attacking juicy vegetable matter, for without doubt they are essentially carnivorous. The larvae of insects, young spiders, mites, and myriapods are their customary food. It is not requisite that the prey should be alive, but they will not touch anything mouldy.
Notwithstanding their apparently weak mouth-parts, they do not merely suck the juices of their victims, but masticate and swallow solid particles. Cannibalism is frequently observed among them.
The males fight fiercely with one another at the breeding time. The females, with their long extrusible ovipositors, place groups of twenty to forty eggs in small holes in the ground or under stones or bark, unprotected by any form of cocoon. The eggs hatch into fully-formed Phalangids, which are at first white, but attain their coloration after the first moult. They subsequently moult from five to nine times.
The distribution of this group is world-wide, and some of the exotic species are very remarkable in form. Only twenty-four species have as yet been recorded in this country.
External Structure.—In the Phalangidea there is no constriction between the cephalothorax and the abdomen, and in the Ischyropsalidae alone is the distinction between them readily observable. This is due to the partial or complete fusion of the first five segments of the abdomen with the carapace or cephalothoracic shield in most species, these segments being indicated, if at all, merely by faint striae or successive transverse rows of spines or tubercles. In the forms possessing hard integuments (Gonyleptidae, Nemastomatidae, Trogulidae) this fusion results in a dorsal “scutum,” the component parts of which cannot easily be distinguished.
The cephalothorax is often surmounted by a turret—usually grooved dorsally, and beset on its edges with a spiny armature—on the sides of which are the two simple eyes. The position and shape of this turret and the arrangement of its spines are of importance in the classification of the group.
Fig. [230].—Hood of Metopoctea. (After Simon.)
In the Trogulidae the base of the turret gives rise to a remarkable, forwardly-directed, bifurcate structure, furnished with numerous strong tubular bristles. This is called the “hood,” and its hollowed-out under surface forms a chamber, the “camerostome,” in which lie the basal joints of the pedipalpi.
In most European Phalangids the under surface of the cephalothorax is almost entirely concealed by the forwardly-projecting portion of the abdomen bearing the generative opening, and by the gnathobases, not only of the pedipalpi, but of the first and sometimes of the second legs. As in Spiders, however, there is always present a “sternum” and generally a “labium.” The sternum is long and narrow in the Mecostethi, and Cyphophthalmi, but in the Plagiostethi, which include most of the forms found in temperate regions, it is very short and transverse, and is hidden by the abdominal prolongation before mentioned.