THE BRITISH WOODLICE. 85
Professor Sars in his Crustacea of Norway (p. 162) describes from Christiania,
under the name of Trichoniscus pygaeus, a still smaller species. As this may
possibly be discovered in this country a brief comparison between it and
Trichoniscus pusillus may be of value. The former reaches
a length of but two millimetres ; it is "whitish, semi-pellucid
with a few light brown pigmentary ramications across the
segments and a double row of irregular opaque patches along
the middle of its back" (p, 163). Its body is covered with
minute tubercles and there are only three joints to the
flagellum ; its movements are by no means rapid.
The body of Trichoniscus pusillus is smooth
and polished. It has four joints to the flagellum
—Dr. Scharff (63) says three or four—and it
moves quickly.
BRITISH LOCALITIES:—
England : Brightlingsea ; Warley ; (W.M.W.) :
Epping Forest ; (Bate and Westwood, 1);
Hanwell; Southall; Kew Gardens ; Langley ;
Burnham Beeches ; Dropmore ; Skirmett;
Bluebell Hill, Maidstone ; (W.M.W.): Chisle-
hurst ; Plymouth ; Polperro ; Looe ; (Bate and
Westwood, 1) : Hertfordshire ; Northumber-
land; Durham; (Norman, 49): Exeter; (Parfitt, 53).
Scotland : Edinburgh ; (Scott, 68): Cumbrae ; (D. Robertson,
Ireland : Connemara ; (Norman, 49): Dublin ; Wexford ; Cork
and Kerry; (Percival Wright teste Bate and Westwood, 1):
Tyrone ; Waterford ; Portlaw ; Kilkenny ;Wicklow ; (Kinahan 33).
FOREIGN DISTRIBUTION:—
Europe: France; (25): Spain; (15): Italy; (19): Norway; Sweden;
Denmark ; Germany; (59).
Africa : Algeria ; Tunis ; Azores; (24).
America : Niagara ; North America ; (59).
Trichoniscus vividus, Koch. Plate IV. (from a spirit
specimen).
1840 Itea vivida Koch (34), part 34, pl. IV.
1858 Philougria vivida Kinahan (33), pp. 197 and 198, pl. XXIII., fig. 2.
1868 Philougria vivida Bate and Westwood (1), Vol. II., pp. 458 and 459, figs.
This species is claret-brown in colour and under a lens it is
seen to be marbled with white, indeed in appearance it is much
like Trichoniscus pusillus though twice the size. There are
important differences between the two species as regards the
number of joints to the flagellum. These vary from five to seven
in Trichoniscus vividus while in the other, as already pointed