AZOREAN GROUP. 19 



added to which, a decided, though small, perforation is clearly 

 indicated in the figure. And I should very much doubt whether 

 its so-called ' American affinities ' are at all more traceable than 

 its Canarian ones. 



(§ Lucilla, Lowe.) 



Hyalina cellaria. 



Helix cellaria, Mull., Hist. Verm. ii. 28 (1774) 



„ „ Lowe, Proc. Zool. Soc. Lond. 177 (1854) 



„ „ Albers, Mai. Mad. 17 (1854) 



„ „ Morel, Hist. Nat. des Acor. 165 (1860) 



Zonites cellarius, Drouet, Faun. Acor. 149 (1861) 

 Hyalina cellaria, Mouss., Faun. Mai. des Can. 15 (1872) 



Habitat ins. omnes (sec. Morelet et Drouet) ; vulgaris. In 

 Sta. Maria etiarn semifossilis occurrit. 



The common European H. cellaria is reported by both 

 Morelet and Drouet to occur on every island of the Azorean 

 Group, varying a little in the different parts of the archipelago. 

 The examples from S. Miguel are said to be, on the average, 

 somewhat larger than those from the other islands, those from 

 Sta. Maria (where it exists likewise in a subfossilized state) 

 more solid, and those from Terceira more convex. It is a 

 species of a widely acquired range, it being eminently liable to 

 accidental introduction through indirect human agencies ; and 

 it has consequently become thoroughly established in the 

 Madeiras and the Canaries, and even at St. Helena. 



(§ Crystallus, Lowe.) 



Hyalina crystallina. 



Helix crystallina, Midi., Verm. Hist. ii. 23 (1774) 

 „ „ Lowe, Cambr. Phil. S. Trans, iv. 47 



(1831) 

 „ „ Albers, Mai. Mad. 17. t. 2. f. 18-21 



(1854) 

 „ „ Morel., Hist. Nat. des Acor. 167 (1860) 



Zonites crystallinus, Drouet, Faun. Acor. 149 (1861) 

 Hyalina crystallina, Mouss., Faun. Mai. des Can. 17 (1872) 



Habitat ins. omnes (sec. Morelet et Drouet) ; sub lapidibus, 

 minus frequens. 



Said by Morelet and Drouet to be found on all the islands 

 of the archipelago, where it has doubtless become naturalized 

 from the European continent. It is a little species which is 

 eminently liable to accidental transmission, along with consign- 

 ments of trees and plants ; and it has consequently gained 

 a footing both in the Madeiran and Canarian Groups. 



c 2 



