136 The Irish Natiualist^ July, 



beautifully variegated with 3'ellowisli markings on a brownish- 

 black ground. There is considerable variation in the 

 colour-arrangement of the specimens I have taken ; some have 

 a broad dark median band running down the dorsal surface, 

 as illustrated in Sars' figure, but the majority have this band 

 divided by a narrow central yellowish line, as shown in the 

 accompanying plate. Most of mj^ specimens measure about 

 8 mm. in length, but one specimen only attains to 6 mm., and 

 one reaches a length of almost 10 mm. This species may 

 easily be distinguished from A. vulga7'e and A. pidchellurn by 

 the shape of the last segment of the metasome, which, in the 

 two species above named, is truncated at the tip, while in A. 

 pidum it is obtusely pointed. The relative lengths of the 

 joints of the flagellum in the specimens taken here differ from 

 those given for this species b}' G. O. Sars. ' In my specimens 

 the proximal joint measures about three-quarters the length of 

 the distal joint, whereas Sars states that the distal joint is more 

 than twice as long as the proximal joint, but Dr. Scharff con. 

 siders this to be obviously an error. 



In the same greenhouses I find that three of our rarer 

 Woodlice — Inchoniscus roseiis^ Koch ; Pojrcl/io dilalahis, 

 Brandt ; and Mdoponorthus prtdnosus, Brandt — are numerous. 



I have to tender thanks to Dr. Scharff, who kindl}' examined 

 ni}' specimens and gave me valuable information in respect to 

 the characteristics and distribution of this species. 



Since the above was in type I find that A. pidutii is 

 exceedingly plentiful in the greenhouses at Bel voir Park, 

 Co. Down ; in fact 49 out of every 50 Woodlice I saw there 

 belonged to this species. 



'' Crustacea of Nonoay, vol. ii., p. 191. 

 Hillsborougli, Co. Down. 



