Rev. T. R. R. Stebbing on Crustacea* 23 



comparing with French examples kindly sent me by M. Adrien 

 Dollfns. The Ventnor specimen, though a small one, agrees 

 with these in relative breadth and in the characteristic feature 

 of the rounded apex of the telson. It differs, however, in 

 colour, not being dark grey on the back, but rather of a dull 

 yellow, faintly marked longitudinally with two narrow ad.ja- 

 cent darkish stripes down the centre. The differences between 

 PorceUio dilatatns and the common Porcellio scaher are suffi- 

 ciently clear, yet that they are not overwhelmingly conspicuous 

 may be inferred from the circumstance that the late Professor 

 Milne-Edwards regarded the former as a synonym of the 

 latter. To the well-known Armadillidium vukjare (Latreille) 

 the English fauna may now add two other well-marked species 

 of the same genus. During last September at Shirehampton, 

 on the Avon, I found the large Armadillidium depressum, 

 Budde-Lund, which is easily distinguished from A. vulgare 

 by the broad projection from the epistome above the frontal 

 line. M. Dollfus has obligingly sent me specimens for com- 

 parison from Rome, and also one from Clifton, near Bristol, 

 bearing the name of Pocock as the donor. Also during last 

 September in Leigh Woods, at Clifton, I found Armadillidium 

 nasatmuj Budde-Lund, which has a narrower but otherwise 

 more pronounced projection than that observed in depressum. 

 In his ' Catalogue of the Land Isopods of Spain ' Dollfus 

 says of this nasatum that it is " esp^ce remarquable par la 

 forte saillie pre-frontale de I'ecusson du prosepistome." Many 

 years ago 1 met with this species at Tunbridge Wells, and 

 supposed it to be a novelty ; but from want of the requisite 

 literature on the subject and pressure of other engagements 

 was forced to lay it aside undescribed. It was again recalled 

 to my remembrance by specimens which my nephew, Mr, Mello 

 Saunders, this year collected for me in l^'rance. 



As the account at present stands there are eighteen species 

 of land Isopods in England to fifteen in Ireland, the only one 

 of the Irish group that has not been found in England being 

 Ti'ichoniscus vividus, Koch. It is not unlikely that fresli 

 species will be found in each of the competing districts when 

 more attention is directed to these crustaceans. At present 

 there are many peo})le to whom the information that there is 

 more than one kind of woodlouse comes as a surprise. 



Terrestrial Isopods of various genera may be assumed to 

 have tastes much in common, for the small limestone quarry 

 at Shirehampton which yielded Armadillidium depressum 

 contained also Trichoniscus roseus, PorceUio scaher, and 

 Oniscus asellus, the specimens of PorceUio and Oniscus being 

 rather exceptionally tine. Such associations are not uncom- 



