14 TESTACEA ATLANTICA. 



other cultivated grounds; but there is no evidence that the 

 nearly-allied T. haliotidea has been observed at the Azores. 



The rather robust, somewhat ancyliform shell of this Testa- 

 cella, which is opaque, usually more or less (as it were) eaten- 

 into and decorticated, and of a pale dingy olivaceous-yellow 

 externally, but which is whitish, shining, and pearl-like within 

 the enormous aperture, will readily distinguish it. The latter is 

 somewhat parallel-sided and oblong ; but the curve at the upper 

 angle of the outer margin is a little interrupted by a slight ex- 

 cavation or sinuosity which is best seen when the shell is 

 viewed from the direction of the nucleus. The lines of growth, 

 although very irregular, are for the most part exceedingly 

 apparent, a few deeper and coarser ones than the rest, filled- 

 up with a brownish deposit, being also more particularly con- 

 spicuous. 



Tarn. 3. VITRJNID^E. 

 Grenus 5. VITRINA, Drop. 

 Vitrina brumalis. 



Vitrina brumalis, Morel., Hist. Nat. des Acor. 146. t. 1. f. 4 



(1860). 



Drouet, Faun. A$or. 146 (1861) 



Pfeiff., Mon. Hel. vii. 22 (1876) 



Habitat S. Miguel ; in Caldeira de Sete-Cidades prsecipue 

 lecta. 



This Vitrina, which is found in S. Miguel, particularly 

 within the Caldeira of the Sete-Cidades, measures about 9 milli- 

 metres across its broadest part; it is excessively thin and 

 fragile, being well-nigh membranaceous ; and its spire is re- 

 markably depressed. Its aperture is largely developed; the 

 lower or columellary border of its peristome is exceedingly 

 narrow, and almost wholly membranaceous ; and (as in the 

 three following species) its spiral whorls are visible from beneath 

 up to their extreme apex. 



Vitrina jnollis. 



Vitrina mollis, Morel., Hist. Nat. des Acor. 147. t. 1. f. 5 



(1860) 



Drouet, Faun. A cor. 144 (1861) 



Pfeiff., Mon. Hel. vii. 22 (1876) 



Habitat Terceira ; inter Angra et Praya copiose deprehensa. 



It is in Terceira that the present Vitrina appears to have 

 been met with, particularly between Angra and the little town 

 of Praya. It is of about the same size as, or perhaps a trifle 



