28 THE BRITISH WOODLICE. 
Oniscus asellus is one of the largest of our woodlice and it is 
also probably the commonest, though Porcellio scabey is in many 
places quite as abundant. The body of Oniscus is broad and 
expanded and the colour is usually a slate grey with yellowish 
markings more or less regularly arranged. 
From the genus Porcellio the species with which we are 
concerned is at once distinguished by the three 
jointed flagellum. Povcellio has but two joints 
and has, besides, a prominent lobe projecting 
from the middle of the head, which is not seen 
in Oniscus. Philoscia, although it has three joints 
to the flagellum, has a narrow abdomen and 
lacks entirely the lateral lobes which are a 
feature of the other genera of Oniscide. 
Oniscus fossor of Koch (34) was recognized by 
Kinahan and by Bate and Westwood as a 
species. Dr. Scharff submitted specimens to 
Professor Budde-Lund who found no differences 
between them and Owmiscus asellus. The former 
(63) mentions, however, that the characteristics 
FIG. 43.—FLAGELLUM of the supposed species are those of young 
AND LAST PEDUNCULAR ‘ 
JOINT OFTHEANTENNA examples Of Oniscus asellus, and Professor Sars 
oF Oniscus aselluce 
(59, p- 173) seems to be of the same opinion. 
Many young examples of Ondscus asellus that we have examined 
have a curious whitish transverse band owing to the light colour 
of the dorsal plates of the first abdominal segments. The 
flagellum also does not seem to shew in young animals a distinct 
division into three joints. 
BRITISH LOCALITIES :— 
England : High Beach, Epping, including an albino; Maldon; 
Brightlingsea; Iver; Hanwell; Eton; Kew; Pamber Forest ; 
Kingston-on-Soar ; Bluebell Hill, Maidstone; (W.M. W.): 
Lynmouth ; (W.M.W. from J.T.C.). 
Scotland; (Scharff, 63). Dinnet, Aberdeenshire; (W.M.W. 
from Madame Christen). 
Iveland : (Scharff, 63). Yellow form with black spots, Donegal 
(R.W.) 
FOREIGN DISTRIBUTION :— 
Europe: Almost throughout; (12): France; (25): Spain; (12): Sweden 
Norway; Denmark: Germany ; Holland ; Italy ; Iceland ; (59): Faroe Islands ; 
Thornsham ; (R.F.S.) 
Africa: Azores; (24). 
America: Greenland ; (59): North America ; (Budde-Lund). 
