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THE OCCURRENCE IN ESSEX OF A SPECIES 

 OF WOODLOUSE (ISOPODA) NEW TO 

 BRITAIN {PORCELLIO RATZBURGI, BRANDT.) 



By WILFRED MARK WEBB, F.L.S. 

 [Read December 16th, !899.] 



HAVING dealt in the Essex Naturalist with the Land and 

 P^resh water Shells of the county in some detail, there seemed 

 to be no likelihood of my making any contribution of importance to 

 the Club upon that subject for some time to come. I, therefore, 

 at our worthy Secretary's request, turned my attention to the 

 collection of Centipedes and Millipedes, classes in which I had 

 already taken a considerable amount of interest. At the same 

 time it was by no means difificuk to secure land Isopods, and it 

 seemed as if the study of our Esse.K Woodlice might produce an 

 addition to our knowledge of the county fauna, with less labour, 

 owing to the smaller number of species. 



Being doubtful of some of my determinations, I submitted a 

 number of Isopods to the Rev. Canon Norman, M.\., F.R.S., 

 who had kindly offered me his assistance. The result was that 

 a specimen of Porcellio was considered by that authority to be 

 Porcellio ratzhiirgi, Brandt, but its antennae being damaged it 

 could not be absolutely determined. Other examples from 

 another locality were too young to make quite sure of, but the 

 species is one, said Canon Norman, that there is reason to think 

 might be found in England. Subsequently I have been through 

 my material from Warley and Brightlingsea, and have picked 

 out two additional specimens from the former locality, after 

 careful examination of the supposed Povcellio ratzhiirgi. Canon 

 Norman now tells me that they belong to that species, which has 

 not hitherto been recorded from this country, and 1 had the 

 pleasure of exhibiting the two woodlice at the meeting of the 

 Club at the Geological Museum, on December i6th. The locality 

 is Warley, and possibly also the species occurs at Brightlingsea, 

 though only immature examples, if any, are in my collection from 

 the latter place. It has been found in Norway, Germany, and 

 France. 



[Owing to the interest of this observation of Mr. Webb's, it 

 seems desirable to publish his note here, somewhat m 

 advance of order of date. — Eu.1 



