HUGGINS : N01ES ON KRITISH MOI.I.USCA. I05 



'in which the band, instead of being blackisii, is of a pale lemon yellow 

 colour, cones{)onding to the var. ochroleuca of H. virgata. 



Helix hortensis. — Mr. J. W. Taylor regards this as a less 

 dominant species than nemoraiis, but so far as my experience goes in 

 this district it is decidedly more dominant, nemoraiis being scattered 

 and comparatively scarce, whereas hortensis, swarms in suitable localities 

 from the top of the chalk downs to the marshes. It is also a very 

 adaptable species, as I have found a few examples on Shorne Mead 

 Saltings, near Gravesend, where all the ground is strongly impregnated 

 witii salt. With the exception of a few mounds all this land is sub- 

 merged at the higher spring tides. All the specimens were white, very 

 large and coarse, and usually much weathered. 



Helix nemoraiis. — A large colony of var. citrinozonata was 

 common four years ago in a reed bed on the Cliff marshes, near 

 Gravesend, the colour being wonderfully adapted to that of the 

 yellow reed stems. 



Limnaea auricularia. — During the past few years I have noticed in 

 this county and also elsewhere the association between adult specimens 

 of this species and broad leaved plants, notably waterlilies and 

 Potamogeton. The full-grown " auriculated " examples in the summer 

 usually appear to sit on the upper surface of the leaves ; it is possible 

 that the great expansion of the lip is caused by this habit, as when I 

 have found "auriculated " specimens where waterlilies do not grow they 

 have always been clinging to piles or wood-work. I have further 

 noticed a tendency on the part of pereger to produce a widely 

 expanded lip where auricularia is found, and at Cobham Park, where 

 auricularia is absent but waterlilies abound, the pereger have the most 

 broadly expanded lips of any I have seen. A similar phenomenon 

 can be noticed in Succinea pfeifferi, when it lives on flags over 

 water the mouth and shell are broad as in piitris, but where it lives 

 on mud in ditches usually almost dry, as in a large colony I recently 

 found in Burwell Fen, the shell is very narrow and the animal appears 

 much less muscular, doubtless from the absence of the muscular 

 exertion required when the species clings to flags above water. It 

 would be interesting to ascertain if water-lilies or wooden piles are 

 found in the Irish localities where the var. acuta only is found, as the 

 lip appears to be developed only in adult examples, and the younger 

 specimens here appear to cling to weed just like pereger. Many 

 young specimens here are almost indistinguishable from the var. acuta, 

 which is what might be expected if the fully expanded lip and 

 swollen body-whorl are recently acquired characteristics due to 

 changed conditions. 



