DISPERSAL BY MAN. 249 



comparatively restricted area within the counties of 

 Hampshire and Sussex, and to a single locality in 

 Surrey ; in Wales, Ireland, Scotland, and the north of 

 England it appears to be unknown. 



Mr. Clement Reid has recently worked out the 

 British distribution of the creature, and at the Linnean 

 Society in December, 1890, he exhibited a map showing 

 its range, together with specimens from " new localities 

 in Sussex." ^ In reply to an inquiry he has favoured 

 me with the following note : 



" The point of my remarks at the Linnean Society 

 was this : I found that H, obvohita^ instead of being 

 confined to a small area on the borders of Hants, and 

 Sussex, extended eastward along the chalk escarpment 

 as far as suitable localities were to be found. The 

 species seems to be very particular as to its habitat ; it 

 must have calcareous soil and plenty of shade, but the 

 ground must never be sodden. It seems also to be an 

 exceptionally sedentary species, for as far as I could 

 see it was confined to ancient woods, and was never to be 

 found in plantations, even if the trees were a hundred 

 years old. 



*' Almost the only place where the necessary conditions 

 are combined is the chalk escarpment, for there we find 

 slopes too steep ever to have been cultivated, and on 

 these, consequently, are preserved many patches of the 

 ancient forest. Nearly all these scattered patches, as 

 far east as the River Arun, are full of Helix obvobita. 



' See "Nature," xliii. (1891), p. 264. 



