BRITISH LOCALITIES:—
England: Warley, Essex; (W.M.W.): Copthorne Common, Surrey; (Stebbing, 70).
FOREIGN DISTRIBUTION:—
Europe: France; (25): Sweden; Denmark; Germany; (59): Turkey; (8).
Family—TRICHONISCIDÆ.
Flagellum with less than ten joints; head with lateral lobes; tail appendages partly hidden.
Genus—TRICHONISCUS Brandt, 1833 (3), p. 174.
Abdomen narrow; eyes compound; flagellum, usually with more than three joints.
In Trichoniscus the flagellum may have from seven to four (rarely three) joints. As in Trichoniscoides and Haplophthalmus there are lateral lobes to the head, though these are not very pronounced; the body is also of small size, the abdomen narrow with both divisions of the tail appendages equally so, and almost of the same length though slightly covered by the last segment. The compound eyes distinguish Trichoniscus from the two genera named, and from Platyarthrus, while its small size and the character of its tail-parts mark it out from all others.
Trichoniscus pusillus Brandt. [Plate III.]
1833 Trichoniscus pusillus Brandt (3), p. 174, pl. IV., fig. 9.
1838 Itea riparia Koch (34), part 22, pl. XVII.
1844 Itea lævis Zaddach (77), p. 16.
1857 Philougria celer Kinahan (32), p. 281, pl. XXII., figs. 1-4.
1858 Philougria riparia Kinahan (33), pp. 191 and 198, pl. XXIII., fig. 1.
1868 Philougria riparia Bate and Westwood (1), p. 456.
1898 Trichoniscus pusillus Sars (59), p. 161, pl. LXXII., fig. 1.