THK MUSEUM. 



75 



The size of the two shells varies — 

 nfiiiornlis is usually i6A iiiiiliineters 

 in height and :2\ in breadth, and /lor- 

 tftisis i6 mm. in height and iS mm. 

 in breadth, and generally the former 

 is more variable in s\ze than the latter. 

 My largest nemoralis is 32 mm. in 

 breadth, and my smallest hoiteusis i i 

 mm. The difference I have especially 

 noticed abroad, where iiiinoialis is 

 often much larger than the average 

 size in England, but hortcnsis remains 

 the same. A third point to be noticed 

 is that it is not usual, though by no 

 means unknown, for the two species 

 to be found in the same habitat. I 

 can only say, in mentall}- reviewing 

 the very many localities in which I 

 have noticed or gathered thousands of 

 these shells, that I can recollect a 

 hedge here and a bank there where 

 both were found mixed and in fairly 

 e(iual proportions. Even here both 

 are found in the same lane, one may 

 be exclusively found at one end and 

 the other at the other. It seems to 

 me, also, that nemoralis is more de- 

 pendent than its cousin, or liortcnsis 

 less dependent than nemoralis, on a 

 calcareous soil. And in a district 

 where both are found nemoralis will 

 affect the parts where the chalk or 

 limestone comes to the surface, and 

 /lortensis will be in the hedges of the 

 valley where alluvial soil to some ex- 

 tent covers the calcareous rock. Have 

 conchologists noticed, by-the-by, that 

 in many places both these shells are 

 common in wayside hedges and on 

 the sides of high roads, but far less 

 common in hedges a field or so 

 distant from the road.' One might 

 have thought that the less amount of 

 cover and the greater amount of ene- 

 mies to be found close to the roads in 

 comparison with field hedges would 

 have reversed the position of affairs. 

 But it seems to me that the dust of 

 the high road provides lime so conven- 

 iently comminuted for the building up 

 of their shells that they have been 

 drawn, so to speak, into public life by 

 its advantages. 



Both shells being in their typical 

 form five-banded, one may notice that 

 the bandless or unicolorous varieties 

 are much more common in /lortensis 

 than in neinoralis, one observer find- 

 ing that 52.52 of the hortensis and 

 only 1 7. 86 of the nemoralis he collect- 

 ed in one district in Middlesex were of 

 the bandless kind. This one might ex- 

 pect from the fact that hortciisis is, on 

 the whole, feebler than its cousin, and 

 so more likely to be without pigment- 

 producing powers, and this is born out 

 by the rarity of the translucent-banded 

 forms in nciuoralis and their compara- 

 tive frequency in hortensis; and also 

 by the variety with only a peripheral 

 band being quite common in nemoralis, 

 but distinctly rare in hortensis. But 

 one must note per eontra, and con- 

 trary to one's expectation, that the 

 variety (sometimes called eoalita) in 

 which form excess of pigment power 

 all the bands are united into one broad 

 belt of chocolate color that occupies 

 nearly the whole whorl, is much more 

 common in the weaker hortensis than 

 in the sturdy nemoralis. 



Other differences are these: The 

 albino form is not uncommon in hor- 

 tensis, though one may notice that the 

 dead white appearance of the shell 

 gives way to a white tinged with yel- 

 low when the animal is extracted; but 

 in nemoralis there is hardly a really 

 albino form, the name var. pallida be- 

 ing more justified than that of var. al- 

 I'ina. The variety lilaeina, again — a 

 tint, by-the-bye, very rare in other 

 Helicidae — is doubtfully found in ne- 

 vtoralis, though abundant in certain 

 localities for hortensis. Nor are the 

 two species at all alike as to unicolor- 

 ous specimens of a brown color. In 

 nemoralis we have the vars. eastanca 

 and olivacea, not rare and giving us 

 many shades, from a dark ruddy brown 

 to a light yellowish brown; but in hor- 

 tensis the corresponding var. fusea is 

 rare, and there is nothing like the ser- 

 ies of shades of brown to be found. 



Another point of difference is the 

 prevalent ground color. Looking at 



