238 CANARY ISLAND FERUSSACLE. 



also the Loveas are eminently liable (like some of the Clausi- 

 lias and Pupae ) to have a state which is more or less shortened 

 and obese, and another which is comparatively elongated and 

 acute. Added to which, the L. attenuata and what I have 

 cited as a 'var B.' of the lanzarotensis are found in company 

 (for the most part in about equal proportions), having been 

 met with hitherto, so far as I am aware, only on the lofty sub- 

 maritime cliffs (known as the Risco, and overlooking the 

 Salinas) in the extreme north of Lanzarote." 



'Even of the L. attenuata, however, as here understood 

 there appears to be a larger and a smaller state, differing in 

 nothing, I think, except in size; and therefore as Mousson 

 speaks of his Cionella attenuata as being conspicuously smaller 

 than the lanzarotensis, it would seem to follow that the com- 

 paratively minute examples of the shell were the only ones he 

 possessed from which to compile his diagnosis. The examples 

 which I have measured vary from 4 to nearly 5^/2 lines in 

 length." (Wollaston.) 



21. P. VITREA (Webb et Berthelot). PI. 40, figs. 45, 46. 



Shell cylindric-fusiform, widest near the base, corneous- 

 yellow, subtransparent, very glossy. Spire gradually taper- 

 ing with somewhat convex outlines. Whorls 5!/2, slightly 

 convex, regularly increasing to the last, which descends much 

 more rapidly, so that in back view the penultimate whorl ap- 

 pears nearly as long as the last. Suture slightly impressed, 

 narrowly opaque-margined. The aperture is subvertieal, 

 ovate, white within. The outer lip in profile is moderately 

 arcuate, and has no well-defined yellow band at the edge. 

 Parietal callus distinct, transparent. Columella white, nearly 

 straight in a front view, but seen to be distinctly truncated 

 obliquely at the base if viewed obliquely in the aperture. 

 Length 6.7, diam. 2.2, aperture 2.7 mm. 



Canary Islands: Lanzarote (Fritsch) ; Fuerteventura near 

 Sta, Maria Betancuria, in the Rio Palmas and on Monte 

 Atalaya (Wollaston). Reported also from Teneriffe, prob- 

 ably in error. 



Achatina vitrea W. et B., Ann. des Sci. Nat. vol. 28, p. 320 



