68 HELICID-. 
It must be remembered that these are merely the flazz 
combinations, and that the various possibilities of eccen- 
tricity, such as extra bands, interrupted bands, etc., are 
practically infinite when combined, as they may be with 
any or all of the groups (a), (b), to (h). Thus it is 
possible to have such a combination as the following :— 
H. nemoralts, m. scalariforme +m. sinistrorsum +v. mayor 
+ compressa + libellula + roseolabtata + rozeozonata, 12345. 
It is perhaps fortunate that there are certain practical 
limits to an infinite series. For instance, in cases where 
a band is wanting, the coalescence of other bands is un- 
common. It is still more uncommon to find examples 
of zemoralis or hortensts possessing the upper and lacking 
the lower banding. The converse of this is also uncom- 
mon, though to a less degree, and confined to certain 
localities in England, though it ismore common in Ireland. 
Perhaps the commonest form is that in which the third 
band alone is present (00300), an additional proof of the 
distinction between this species and ortensts, which is 
very rarely marked thus. The suppression of the third 
band alone is rare in both species alike. 
' Var. I. mdjor (fér.). Diam. 28mm. (after 
Pascal). 
a. SIZE. 
| Var. II. minor (Mog.). Diam. 16mm. (after 
Pascal). 
\ 
b. texture. Var. III. pdnderdsa (Malm). Shell thicker 
and heavier. 
