THE ASSOCIATION OF HELIX NEMORALIS 

 AND HELIX HORTENSIS. 



By the Rev. S. S. PEARCE, M.A., Long Combe Vicarage, Woodstock, Oxon. 



(Read before the Society, December lo, 1902). 



During the last twenty years in which I have been interested in our 

 land and freshwater molluscs I have only taken the two species in 

 association together at the five undermentioned localities. 



1. On the chalk downs among furze bushes above Paradise Wood, 

 near Eastbourne, East Sussex, April, 1884. Formation : Middle 

 chalk. Helix nemoralis occurs here in hundreds and associated with 

 a very few H. Iiorfeiisis. The shells are for the most part 12345, 

 and though of the colour forms v. libellula and v. lutea respectively, 

 the yellow in each species is practically lost the shells having a white 

 bleached appearance. I may add that in the Eastbourne and Lewes 

 districts of Sussex both species are plentiful, but confined to their 

 respective habitats; H. nemoralis is chiefly found on the downs and 

 in woods on their flanks, whereas H. hoi'tensis keeps to the hedges, 

 etc., of the lower lands such as Pevensey levels. 



2. By the side of a track or green lane leading up to Boniface 

 Down from Shanklin old church, I. of W. Both species were taken 

 together, with several examples of H. arbustorurn. This is the 

 only case of association I can record in the island, though I know the 

 whole of it very well, and both species abound in distinct localities. 

 Formation: Lower chalk. Date, August, 1881. 



3. Outside the village of Yelverton, near Norwich, in a lane leading 

 to the latter city, the two species were associated together in a living 

 state in considerable abundance. Helix nemoralis predominated in 

 all its commoner forms of v. libellula and v. rubella; H. hortensis 

 was confined to its varieties 7///m 00000 and a few 12345. Formation: 

 Glacial drift. Date, several occasions between September, 1889 and 

 December, 1890, 



4. I submit also the following evidence as to the association of the 

 two species. \x\ July, 1901, an unfrequented lane at Goodrington, 

 between Paignton and Totnes, S. Devon, yielded the following 

 numbers of recent bird-eaten H. nemoralis and H. hortensis inextricably 

 mingled together with a few examples of H. aspersa. The numbers 

 taken were H. nemoralis 3 1 , H. hortensis 403. Formation : ? 

 Date, July 15 and 16, 190 1. 



5. A collection of shells of H. nemoralis and H. hortensis recently 

 broken by birds for food taken at the foot of limestone cliff at Anstey's* 

 Cove, S. Devon, Date, July 29, 1901. Helix nemoralis largely 



