MOLLUSCS 



The soil and climate of Sussex, as well as its diversified physical 

 features, are favourable to moUuscan life. The chalky south downs 

 swarm with some species, which it is even claimed are the cause of the 

 excellent flavour of the mutton grown in that district ; the woody copses 

 and remnants of the Wealden forest shelter others ; while, though there 

 are no very large rivers, the numerous streams, especially of the 

 Pevensey Level, yield a great number of aquatic forms. 



Out of the 139 species known to inhabit the British Islands, no less 

 than 105 have been recorded as occurring in the county. Among these 

 we have not reckoned the Roman snail {Helix pomatid) because the sole 

 evidence of its presence depends on a single dead shell found in the Lady 

 Holt covers near Harting, and though an attempt was subsequently 

 made to establish a colony there it did not succeed. Why this species, 

 so abundant on the north downs, should be absent from such an 

 apparently equally favourable situation as the south downs is a mystery. 

 A few other absentees, such as Vitrea glabra, some of the Vertigos and 

 of the slugs, may yet be discovered. 



The assemblage is of the average British type with the addition of 

 two forms of interest, viz., Helicella cartusiana and the cheese snail 

 {Helicodonta obvoluta), which last local species has been traced by Mr. 

 Clement Reid, F.R.S., along the northern escarpment of the south downs, 

 in ancient beech woods, from Harting to the river Arun, with a few 

 colonies in the middle of the downs towards West Dean and Singleton. 



The literature of the subject is very scattered, but the more 

 important papers are those by Mr. J. E. Harting' and Mr. J. H. A. 

 Jenner,^ the latter which deals with East Sussex including the work of 

 all previous writers. 



A. GASTROPODA 



I. PULMONATA Agrwlimax agn-stis (Linn.) 



_ /a^is (Mull.) 



a. StYLOMMATOPHORA . ,■ ^ ;-/ir( \ 



Amalia iowerbti [r er.) 



Testacella scutu/um, Sby. Lewes. (Specimens — gcgi'ta (Drap.) Hastings 



from Newport, Isle of Wight, have Vitrina pcllucida [MuW.) 



been turned loose at Chichester) Fitrea crptallina (Mull.) 



Limax maxirnus, Linn. — alliaria (Miller) 



— flavus, Linn. — cellarui (Mull.) 



— arborum, Bouch. -Chant. West Sussex — nitidula (Drap.) 



1 Zoologist, 1878, pp. 84, 122, 161. 



* Trans. Eastbourne Nat. Hist. Soe. vol. viii. (1884) p. 44 ; and supplement Jourv. Conch, vol. vi. 

 (1891) p. 361, to which <T few more species have been added by Mr. W. Whitwell, ibid. vol. x. (1901) 

 p. 86. 



108 



