The Irish Wood-lice. 27 



Porcellio pictus, Braudt (fig. 7). 



In size this species differs but little from the preceding one, and 

 although it bears a certain resemblance to some of the spotted forms of 

 P. scaber, the general colouring distinguishes it at once from all other 

 species. The head is entirely black, and the black and yellow markings 

 on the body are arranged in regular rows. It is also much less granu- 

 lated than the last species. 



It is one of the rarest of the Irish species, having only been found in 

 Dublin and Belfast (5) in rather dry localities among stone rubbish. 



General Distribution.— England (Kent only) (i), N., \V., C. & E. 

 Europe and N. America (2). 



Porcellio dilatatus, Brandt (fig. 8). 



This species is generally slightly larger and much broader than P. scaber, 

 and the outer antennae are a little shorter. The terminal caudal 

 segment is rounded at the tip, not pointed as in P. scaber. The colour is 

 grey, rather similar to that of the latter species, but it has a longitudinal 

 series of white tubercles arranged down the middle of the back, and the 

 surface is less strongly granulated. 



It is extremely rare in Ireland, and has been found only in Dublin (5) 

 along with P. scaber. It has not been recorded from England. Abroad it 

 lives chiefly in cellars. 



General Distribution. — C. and W. Europe, and Cape York, 

 (Australia) (2). 



Porcellio Iaevis, Latr. (fig. 9). 



The very smooth and shining surface of the back distinguishes this 

 species at once from the three preceding species of Porcellio. It is 

 larger too than any of the others, and the caudal appendages are of 

 great length. There are often two series of yellowish markings arranged 

 longitudinally along the back, and the under side of the body and legs 

 are yellow. The terminal segment of the tail is triangular and shorter 

 than in the other species. The colour is greyish-purple. 



Like the last, it is a rare species, having been found only in Dublin 

 among stable-litter and at the foot of old walls (5). 



General Distribution. — S.E. of England only (1), C, \V., and 

 E. Europe, Mediterranean Islands, Turkey, Turkestan, W. Indian 

 Islands, N. and S. America, &c. (2). 



Cyiisticus convexus, De Geer (fig. 10). 



Porcellio armadilloides, Kin. 



In shape, this species reminds one strongly of Armadillidium vitlgare 

 (fig. 17), and like the latter, it is able to roll itself into an almost perfect 

 ball, which cmality is possessed by none of the other Irish Wood-lice to 

 the same degree, although some of them make an attempt at rolling 

 themselves up partially. The upper surface of the body is very convex 

 and shining, of an iron-grey colour, with a row of ill-defined whitish 

 .spots parallel with the lateral margins. The caudal appendages are 

 styliform, as in all other species of the genus. 



Prof. Kinahan does not record this species from Ireland, and I myself 

 only recently discovered it under stones in a disused quarry at L,eixlip, 

 County Dublin. It runs with great agility. 



General Distribution.— S. E- England only (1), Scotland (9), N. C, 

 and E. Europe, Turkey, N. America. 



