ON SOME VARIATIONS IN HELIX ARBUSTORUM. 409 
The amount of variation exhibited in specimens coming from 
the same spot is very striking, and led to my enquiring into the 
value of the named varieties (so-called) of this species. The 
conclusion was irresistible that, however useful such distinctions 
may have been in the past, they are totally inadequate to 
present requirements, not to say unscientific, whilst their reten- 
tion is even mischievous in encouraging too close an insistence 
on trivial and valueless minutiz to the overlooking of the broader 
generalisations that underlie them; and this is true of other 
species equally with the one at present under consideration. 
In the first place, of course, I sought for the var. Baylei, 
Lecoq., which was said to be new to Britain. The description 
given by Moquin Tandon* as follows :—‘‘ v. Baylei (Lecoq.! in 
litt.). Coq. plus petite, plus conoide, extrémement mince, fort 
transparente, d’un jaune verdatre clair, unicolore.” 
What may be implied by the ! after Lecoque’s name I cannot 
ascertain ; but it is evident that he never published a description 
of it, and it is at best a MS. name. 
Many of the immature specimens in the collection answer 
very well to this description. They are perfectly transparent, 
extremely thin, and destitute of any markings whatsoever 
(reminding one strongly in these respects of Vitrina pellucida, 
Mull.+ (a likeness enforced by the presence of a dent in one 
specimen, showing that the shell was quite soft when the animal 
was extracted); the colour, too, is greenish yellow. These 
specimens, however, are matched in every respect, save that of 
colour, by other examples, also immature, from the same 
locality, the tint in these cases being a pale red-brown. More- 
over, amongst the adult specimens, both fulvous and rufous, it 
is by no means uncommon to find examples in which the upper 
33, or even 4, whorls are manifestly free from markings of any 
kind, thus showing that in their youth they, too, resembled the 
specimens just described, till at a given period of their growth, 
and immediately after an evident pause in the same, they 
acquired (sometimes quite suddenly) the full markings of the 
typical form. 
* Hist. Nat. Moll. France, ii. p. 124. 
+ Mr. J. W. Taylor also notes this similarity of texture (Journ. Conchol 
lil. p. 253, 
