102 



and close to the margin, with often a tubercle on 

 , its outside. ... 



The distortion of the peritreme clearly places this 

 species among the vertiginous or wry-mouthed 

 tribe of the Pujnlladce. 



82. VERTIGO Anglica. Aperture five-toothed : the 

 peritreme flattened and reflected. 



Vertigo Anglica. De Ferussac, Mollusc. 



Shell two lines long, and half as much broad, dark 

 chocolate-brown with often a greyish cast, especi- 

 ally towards the point, opake, faintly striate lon- 

 gitudinally : spire composed of six or seven slightly 

 raised volutions : aperture semielliptic, with a 

 tubercular projection near the top of the outer lip, 

 and five teeth ; two at the base, one of them small 

 and tubercular, one central at the top ; one at the 

 top of the outer angle, parallel with and united to 

 the peritreme, curving so as nearly to meet the 

 marginal tubercle, and form a circular inclosure ; 

 and an oblique one on the pillar : peritreme flat, 

 brown, reflected, with a strong umbilicus behind 

 the pillar. 



In the half-grown shell, the teeth appear round the 

 circumference of the base, nearly at equal distances, 

 like pieces of white enamel. 



