202 TEST ACE A ATLANTIC A. 



Sectio I. INOPERCULATA. 



Fam. 1. HELICID^. 



Grenus 1. HELIX, Linne 



(§ E'uparyiJlm, Hartm.) 



1. Helix pisana. 



Helix pisana [var,], Miill.^ Verm. Hist. ii. 60 (1774) 

 „ ustulata, Loive, Ann. Nat. Hist. ix. 114 (1852) 

 „ MacAndrewiana, Pfeiff., Mon. Hel. iii. 625 (1853) 

 „ ustulata, Lowe, Proc. Zool. Soc. Lond. 171 (1854) 

 „ MacAndrewiana, Paiva, Mon. Moll. Mad. 71 (1867) 



Habitat ins. Salvages ; in aridis calcariis, abundans. 



The particular Helix which represents at the Salvages the 

 European H. pisana has so remarkable an aspect that it might 

 well be regarded, at first sight, as specifically distinct. And 

 indeed both Dr. Pfeitier and Mr. Lowe have thus disposed 

 of it, — the former imder the name of H. MacAndrewiana, 

 and the latter under that of H. ustulata ; yet I am satisfied, 

 after a very careful consideration, that it does not possess fea- 

 tures of sufficient importance to warrant its being treated as 

 separate — its peculiarity of sculpture being in exact accordance 

 with that of the pisana, whilst even its coloration (beautiful 

 though it be) is not 'more singular than what obtains in certain of 

 the other permanent (but undoubted) varieties of the latter. In- 

 deed, apart from colour, we can merely define it as (on the 

 average) a little thinner and more globose than is usual in the 

 more northern type, — its basal whorl being a trifle more inflated, 

 and therefore utterly free from every trace of a keel. But these 

 points, as well as its nearly closed-up perforation, are all paral- 

 leled in recognised states, and examples, of the pisana ; and 

 we have nothiag, therefore, left for us to fall back upon but 

 its very remarkable hue ; whilst even this ceases to be dis- 

 tinctive when I mention that there are tivo well-marked phases 

 of the shell on the Salvages, one of ivhich is pure luhite 

 with only the peristome rosy, and that this so closely resem- 

 bles the ordinary pallid one of the pisana that, after acciden- 

 tally mixing them together, I have experienced the greatest 

 difficulty in re-separating them in accordance with their respec- 

 tive habitats. 



I have already mentioned, however, that the normal 

 aspect of this elegant Salvages shell is most extraordinary, — 

 the examples which are not white being more or less sufifused 



