434 JOURNAL Ot CONCHOLOGY. 



NOTES ON MOLLUSCA AT CANTERBURY. 



By The Rev. J. W. HORSLEY, M.A. 



(Read before the Conchological Society, 22iid August, 1894). 



During a short visit to Canterbury I found Helix cartusiana 

 var. vdnor and one specimen of var. alba at Barham Downs ; also 

 a colony of ^ hortensis 00300 at Stuppington. Why this variety 

 should be so rare in H. hortensis and so common in H. nemoralis 

 always puzzles me. Wherever I have found it, it prevails over 

 any other variety of H. hortensis in the same hedge. At Upper 

 Hardres I found plentifully, on a somewhat barren hill-side, 

 H. virgata var. alba and var. hyalozonata. Something in the 

 nature of the soil or its vegetation was unfavourable to the 

 development of pigment, as the var. albescens was still more 

 plentiful, and the type and the var. subniaritinia comparatively 

 rare ; and also H. ericetoriim and H. cantiana were mainly 

 white or whitish, though H. caperata (the only other Helix I 

 noticed in the field) was well marked and coloured. This was 

 the first time I had taken var. alba, and I may note the differ- 

 ence between it and V2ix. albescens: — (i). When the animal is 

 extricated the shell is so pure white as to deserve the name of 

 candidissinia, whereas that of albescens has always a yellowish 

 tinge. (2.) The tip is pure white and well defined — that of 

 albescens less strong and always reddish. (3). The shell of alba 

 is more transparent and the body of the animal, I think, blacker, 

 the result being that alba on the grass has a distinctly slate or 

 bluish tint, so much so that my young children at once distin- 

 guished between what they called the white {albescens) and the 

 blue {alba) shells, and brought me only the latter. And when 

 alba is banded (which it frequently is, white albescens .is never) 

 the dark body seen through the transparent bands seems defin- 

 itely bluish-grey, not at all like the black or brown bands of 

 the typical Helix virgata. 



St. Peter's Rectory, Walworth. 



.I.e., vii., Oct. 1894, 



