JOURNAL OF CONCHOLOGY. 21'j 



Planorbis dilatatus Gould. — I see in the Conchological 

 Society's list of British shells that this species has been put in 

 brackets, tfut I think it may be put down as a naturalized 

 British species. I think the theory of my friend Mr. T. Rogers, 

 who first discovered this species, is very likely to be the true 

 one, as one can readily think it must have been introduced 

 from America in cotton. I have not tried for some years to 

 get it at Pendleton, where Mr. Rogers first found it, as the last 

 time I was there they had been repairing the towing-path side 

 of the canal, and had put down a large quantity of new stones 

 at the place where J^. dilatatus used to be found, and also the 

 water had become much worse, so much so that S. ovale, which 

 used to be found there in plenty, had all died away. The other 

 locality at Gorton where Mr. Rogers found it, I have got them 

 at repeatedly — some last season (1883), but not in any great 

 quantity. Mr. Rogers found them close to Ryland's mill at 

 Gorton, near where the warm water from the mill ran into the 

 canal, but now we do not find them there at all, but about a 

 quarter of a mile away where the water is quite cold ; I think 

 therefore we may conclude that they are fully naturalized, as it 

 is now fourteen years since Mr. Rogers first found them. — 

 E. Collier, Manchester. 



Arion ater var. bicolor in West Gloucestershire. — 



On the 1 2th of May Mr. E. J. ElUott sent me, along with a 

 number of specimens of Zonites nitidus from Brimscombe near 

 Stroud, in the Western division of Gloucestershire, several 

 immature scarcely half grown examples of the var. bicolor of 

 Arion ater, fairly characteristic, although hardly so brilliantly 

 coloured as the Irish ones I have previously had. It is interest- 

 ing to note that in both instances the locality which produced 

 this variety was a boggy or wet place. Mr Elliott found it 

 with Z. nitidus in marshy spots, generally concealed among the 

 wet mosses. — W. Denison Roebuck, Leeds, May i8th, 1884. 



