AZOREAN GROUP. 29 



The present Helix, which was described by PfeifFer from 

 examples communicated by the late Mr. Cuming, is said to be 

 from S. ]Miguel ; but it was not met with either by Morelet or 

 Drouet. There can be little doubt that it belongs to much the 

 same type as these immediately allied forms, though its white 

 colour and more solid substance, in conjunction with the fact 

 that its ultimate whorl does not appear (judging from the pub- 

 lished diagnosis) to be at all deflected at the aperture, show it 

 to be speciiically distinct from them all. 



In his observations on the H. niphas, Morelet says : ' II est 

 evident que cette espece se rattache par des liens etroits au 

 groupe que nous venons d'etudier ; ainsi la taille, la forme glo- 

 buleuse, la spire conique, I'absence d'ombilic, le peristome droit, 

 epaissi au point d'insertion, enfin la direction de la columelle, 

 sont des caracteres communs a toutes les coquilles de cette 

 serie. Le nombre des tours de spire, leur developpement 

 graduel et la simplicite du bord droit, se retrouvent en outre 

 chez VH. caldeiraruni, dont I'espece de M. Pfeiffer semble se 

 rapprocher d'avantage ; mais elle en differe, ainsi que de toutes 

 les autre?, par la solidite, la couleur, et la direction du dernier 

 tour de spire qui ne flechit pas a sa terminaison.' 



Helix terceirana. 



H. caldeirarum (pars). Morel, et Dr., Journ. de Conch, vi. 



150 (1857) 

 „ Terceirana, Morel., Hist. Nat. des Agar. 158. t. 2. f. 4 



(1860) 

 „ „ Drouet, Faun. Agor. 152 (1861) 



Habitat Terceira ; inter arbusculas Myrsine retusa, necnon 

 sub lapidibus, in Caldeira, copinse lecta. 



Apparently very nearly allied to the H. caldeiraruni, but 

 found in Terceira instead of S. Miguel. It appears to be com- 

 mon in that particular island, where it was found by Morelet 

 and Drouet beneath stones and about the bushes of Myrsine 

 retusa, in the great Caldeira. 



The H. terceirana is more solid, less diaphanous, and more 

 coarsely striated than the caldeirarum (indeed it is said to be 

 sometimes quite free from gloss) ; its ultimate whorl is rather 

 more flattened beneath ; and its peristome is more thickened or 

 bordered internally, and has the columellary margin gradually 

 more flattened or dilated towards its point of insertion. Its colour 

 too is different, — the darker zone of the H. caldeiraruni being 

 absent, and the surface usually more or less faintly freckled with 

 subopake and slightly paler fragmentary markings. 



