16 TESTACEA ATLANT1CA. 



Flores ; but it does not appear to have been observed in any of 

 the other islands. 



Vitrina angulosa. 



Vitrina angulosa, Morel., Hist. Nat. des Acor. 191. t. 2. f. 1 



(1860) 



Drouet, Faun. Acor. 144 (1861) 



Pfei/., Mon. Hel. vii. 23 (1876) 



Habitat Sta. Maria ; ad basin montis Pico Alto parce 

 reperta. 



This is the smallest of the Azorean Vitrinas, measuring only 

 6 millimetres across its widest part ; but, not to mention its 

 diminutive bulk, it may be recognised by its ultimate volution 

 (which is, in proportion, largely developed, and somewhat convex 

 beneath) being appreciably angulose. The colour seems to be of a 

 more brownish-, or even reddish-, green than is usually the case 

 in this genus, and its whorls are about three in number. It was 

 found in Sta. Maria, at the base of the Pico Alto, and would 

 appear to be scarce. 



Vitrina laxata, 



Vitrina laxata, Morel., Hist. Nat. des Acor. 144. t. 1. f. 3 



(1860) 



Drouet, Faun. Acor. 142 (1861) 



Pfei/., Mon. Hel. vii. 21 (1876) 



Habitat Sta. Maria, et S. Miguel ; in convallibus umbrosis 

 praecipue degens. 



The V. laxata is the largest of the Azorean Vitrinas 

 (measuring about 12 millimetres across its widest part), and one 

 which is said by Morelet to approach nearer than the others to 

 the ordinary European types, particularly to the V. diaphana. 

 It is extremely thin and fragile, with the ultimate whorl very 

 broadly developed or produced, causing the aperture to be ex- 

 ceedingly large or elongated ; and, as in the V. pelagica, the 

 upper and lower margins of its peristome (the latter of which is 

 bordered by a narrow membrane) are connected across the body- 

 volution by an extremely faint lamelliform thickening. 



The present Vitrina is found in Sta. Maria and S. Miguel, 

 in the former of which islands a variety is said to occur which is 

 a little more globose and also a trifle less fragile. 



Vitrina pelagica. 

 Vitrina pelagica, Morel., Hist. Nat. des Acor. 143. t. 1. f. 2 



(1860). 



55 Drouet, Faun. Acor. 143 (1861) 



Pfei/., Mon. Hel. vii. 21 (1876) 



