AZOREAN GROUP. 17 



Habitat Sta. Maria ; sub lapidibus, et cast., versus Pico Alto 

 deprehensa. 



The present Vitrina, which is found about the Pico Alto in 

 Santa Maria, is apparently a trifle less fragile, and more Helici- 

 form in its contour, than the other species, — its less largely 

 developed aperture and the widened and somewhat convex base 

 of its ultimate whorl, in conjunction with the margins of its 

 faintly thickened peristome being connected by an extremely 

 thin intervening lamina, recalling somewhat the V. Blauneri 

 which is so characteristic of Grand Canary. Its proportions 

 however are not quite the same as those of that species, its 

 spire is less flattened, and the columellary edge of its lower lip 

 is narrowly and shortly expanded and subreflexed, — forming 

 (according to the diagnosis) a kind of very minute umbilical 

 fossette or chink. 



Fam. 4. HELICID^. 

 Genus 6. HYALINA, Gray. 



(§ Radiolus, Woll.) 



Hyalina volutella. 



Helix volutella, Pfeiff., Proc. Zool. Soc. Lond. 33 (1856) 

 „ brumalis, Morel, et Dr., Joum. de Conch, vi. 149 

 (1857) 

 Zonites brumalis, Mouss., Viert. der Nat. Zurich, 164 



(1858) 

 Helix volutella, Pfeiff., Mon. Eel. iv. 102 (1859) 



„ „ Morel., Hist. Nat. des Acor. 166. t. 3. f. 1 



(18b0) 

 Zonites volutella, Drouet, Faun. Agor. 148 (1861) 



Habitat ins. omnes (sec. Morelet et Drouet) ; sed vix 

 abundans. 



A very beautiful little Hyalina which, according to Morelet 

 and Drouet, is found on every island of the Group. It is ap- 

 parently peculiar to the Azores ; and, judging from the diag- 

 nosis and figure, it has much the same discoidal outline as the 

 H. cellaria, but is considerably smaller and with a more minute 

 (but nevertheless very deep) umbilicus ; and its volutions are 

 transversely striped, or radiated, with reddish-brown, or yellowish- 

 red, bands. It appears to be subject to slight modifications in 

 the different parts of the archipelago, — the examples from Fayal 

 and Sta. Maria having their spire more elevated than those 

 from S. Miguel, as well as their striae more distinct (which 

 latter fact is said to diminish somewhat their brilliancy) ; whilst 

 those from Graciosa, on the other hand, are not only (when 



c 



