26 The Irish Naturalist. 



Trlchonlscus puslllus Brandt (fig. 3). 



Philougria riparia, Kin. 



This is the smallest of the Irish species, a full-grown specimen 

 measuring only 3} mills, iu length. It is of a claret-brown colour, smooth 

 and shining in texture, and dotted over with exceedingly minute white 

 spots. The outer antennae are a trifle too long and broad in my figure ; 

 three or four articulations make up the flagellum. As in the other 

 species of the genus, the tail is very distinctly narrower than the body. 

 The last caudal segment is deeply excavated over the insertion of the 

 posterior appendages. Trichoniscus pusillus is found only in very damp 

 places amongst moist leaves and under stones, and it runs with great 

 agility. 



It is a very common species throughout Ireland. 



General Distribution. — Widely distributed in England (1), and 

 Scotland (9), W., N., and Central Europe, Algeria and N. America (2). 



Trlchonlscus vivldus, Koch (fig. 4). 



Philougria vivida, Kin. 



In colour and texture this species agrees almost precisely with 

 the last, but it is about double the size, and the flagellum has 5-7 

 articulations, instead of 3-4 in the other. The outer antennas are 

 also devoid of the hairs or setae by which the other two species of 

 Trichoniscus are distinguished, and the last caudal segment is not 

 excavated (emarginate). 



This species has been taken under stones on the hills at Portlaw, Co. 

 Waterford (5), the only locality in the British Islands. 



Generae Distribution.— France (2). 



Trichoniscus roscus, Koch (fig. 5). 



Philougria rosea, Kin. 



A beautiful light vermilion colour, with a pale yellow stripe down its 

 back, distinguishes this species at once from all other British Wood-lice. 

 Occasionally perfectly white specimens are found, and in spirit they all 

 turn white. 



This species has not been recorded by Kinahan. I found it plentifully 

 in my own garden in Dublin among damp cinders in autumn ; and I 

 have, quite recently, received from Mr. R. Welch a box-full of clay from 

 Ballyfinder, Co. Down, in the crevices of which I found an example of 

 this very rare species. 



Generae Distribution. — Plymouth in England (1), W. and C. 

 Europe, Italy, Dalmatia, Algeria (2), New Zealand (10). 



ONISCIDJE. 



Porcellio scaber, Latr. (fig. 6). 



This and Oniscus asellus are the two commonest species in Ireland, 

 and they principally do the damage to tender shoots in the green- 

 house. The colour is generally of a uniform grey-slate, but numerous 

 varieties occur, some being irregularly dotted with yellow; in others 

 yellow becomes the prevailing colour. The strongly-marked tubercles, 

 covering the whole of the back, are the most conspicuous feature. The 

 flagellum, as in other species of this genus, has only two joints, and they 

 are about equal in length in Porcellio scabcr. 



It is common everywhere in Ireland in damp as well as in moderately 

 dry situations. 



Generae Distribution. — Common in England (1), and Scotland (9), 

 N. and C. Europe, N. America, Greenland and Cape of Good Hope 

 (2). 



