Fig. [237].—Nemastoma lugubre.
There is but one genus, Nemastoma, in this family, and the members of it are, as a rule, rather small and dark Phalangids, which live under stones or in moss or débris, and are found in the mature state at all seasons of the year. There are about twenty European species, but only two of these, N. lugubre and N. chrysomelas, have as yet been found in Britain. N. lugubre is a very common animal, and though it does not obtrude itself upon public notice, its little black body with two pearly white spots must be a familiar object to all insect collectors who have occasion to search under stones or among moss in damp places. Its legs are short and stout, but those of N. chrysomelas, which is a brighter coloured Harvestman with spots of dull gold colour, are long and slender.
Fam. 4. Trogulidae.—Coriaceous and very hard integument. Anterior part of cephalothorax produced into a bifurcate “hood.” Often a “trochantin.”
Fig. [238].—Trogulus aquaticus. a, Hood. (After Simon.)
The Trogulidae are very slow-moving Phalangids of moderate or large size (a sixth to half an inch in body), found under stones or in damp moss and débris. They are Mite-like in general appearance, and may readily be distinguished from all other Harvestmen by the presence of the “hood” (Fig. [230], p. 442), the hollowed-out under surface of which forms a chamber, called by Simon the “camerostome,” in which lie the basal portions of the pedipalps.
Only a single immature specimen has been found in England, belonging probably to the species Trogulus tricarinatus. It was found in Dorsetshire. Some members of the family are not uncommon in various regions of the Continent. There are four genera, Dicranolasma, Anelasmocephalus, Calathocratus, and Trogulus. Two other genera, Amopaum and Metopoctea, have been established, but the former is probably the young of Dicranolasma and the latter of Trogulus.
According to the monograph on the British Phalangidea by the Rev. O. Pickard-Cambridge, cited above, the following species have been recorded in this country. They all fall under the sub-order Plagiostethi:—
BRITISH PHALANGIDEA.
Phalangiidae.