AZOREAN GROUP. 25 



Judging from the diagnosis, and the admirable figure which 

 is given by Morelet, I am inclined to think that the present 

 Helix, which has been found hitherto only in a subfossil condi- 

 tion in the south of Sta. Maria, is perhaps more akin to the 

 likewise subfossilized H. chrysomela, Pfeiff. (particularly the 

 larger state of that species, which was subsequently described 

 by Lowe under the name of fluctuosa], than it is to anything 

 else which has yet been brought to light in the various Atlantic 

 archipelagos. Prima facie it has undoubtedly somewhat in 

 common with certain Canarian members of the Lemniscia sec- 

 tion, such as the H. tumulorum and phalerata ; but in no 

 instances are they wholly imperforate, neither are the margins 

 of their peristome connected by a decided lamelliform callosity; 

 and although this latter character is by no means distinctive of 

 Leptaxis proper, but quite the reverse, it nevertheless is strongly 

 expressed in the H. chrysomela which it is quite impossible 

 to remove from the same actual group which embraces the 

 erubescens and membranacea types. Moreover it appears to be 

 present also in the (equally extinct) H. atlantidea, Morel., from 

 the Cape Verdes. The rather straightened and thickened lower 

 lip, too, is much in accordance with what one observes in the 

 Porto-Santan H. chrysomela ; while its strongly pronounced 

 keel, and what little we are able to trace of its colouring, are 

 marvellously suggestive of that same species. 



Whether the H. vetusta (which measures about 19 milli- 

 metres across its broadest part, and has an altitude of about 11) 

 belongs altogether to a past epoch can hardly be decided, until 

 the numerous submaritime districts of Sta. Maria have been 

 more carefully explored. 



Helix erubescens. 



Helix erubescens, Lowe, Cambr. Phil. S. Trans, iv. 40. t. 5. 



f. 3 (1831) 

 et simia, Pfeif., Hon. Hel. i. 270 et 288 



(1848) 



Lowe, Proc. Zool. Soc.Lond. 165 (1854) 



Alb., Mai. Mad. 47. t. 12. f. 11-16 



(1854) 



Morel., Hist. Nat. des Acor. 153 (1860) 



Drouet, Faun. Acor. 150 (1861) 



Paiva, Mon. Moll. Mad. 13 (1867) 



Habitat S. Miguel ; in citranetis, prsesertim intra cavernas 

 arborum et sub cortice laxo, sat copiose latitans. 



The very beautiful, but inconstant, H. erubescens, which is 

 so universal (under various modifications both of contour and 



