84 THE BRITISH WOODLICE. 



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— TRICHONISCID^E. 



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 Trichoniscns the flagellum may have from seven to four 

 (rarely three) joints, As in Trichoniscns and tiaplophthalmus 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 Trichoniscns 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, pi. IV., fig. 9. 



1838 Itea riparia Koch (34), part 22, pi. XVII. 



1844 Ilea lecvis Zaddach (77), p. 16. 



1857 Philougria celer Kinahan (32), p. 281, pi. XXII., figs. 1—4. 



1858 Philougria riparia Kinahan (33), pp. 191 and 198, pi. XXIII., fig. 1. 

 1868 Philougria riparia Bate and Westwood (1), p. 456. 



1898 Trichoniscus pusillus Sars (59), p. 161, pi. LXXII, fig. 1. 



This tiny species is found commonly amongst the roots of 

 the herbage in very moist places. It presents a horny translucent 

 appearance and is of a reddish brown colour. It runs with 

 considerable speed, and when it is moving, the white irregular 

 lines with which it is beset are not evident. Trichoniscus pusillus 

 is very much like Trichoniscus vividus in colour but the latter 

 species is nearly twice as big and has from five to seven joints 

 to the flagellum, while the former has never more than four. 

 Trichoniscus roseus is also much larger and its bright red colour 

 (which it loses, however, when preserved in alcohol) is 

 another means of distinguishing it from the species under 

 consideration. 



