GASTEROPODA. HELICIDZ. 93 
1. VerTIGo patustris. Pl. 8. fig. 10. 
V. testa ventricosa, apertura 8-dentaté: dentibus 3 posticis ; 
3 anticis; 1 dextro et 1 sinistro. 
- Turbo sexdentatus, Mont. Test. Brit. 337. 
Pupa antivertigo, Drap. Hist. des Moll. 60. pl. 3. figs. 32, 33. 
f. apertura 9-dentata. 
Habitat in paludibus. 
Testa intensé fusco-badia, peritremate albido. Apertura den- 
tibus dissimilibus: dentes tres antici ineequales ; sinister bre- 
vior, medius longior: dens sinister ceeteris crassior: dens 
dexter minutus, tuberculiformis : dentes postici insequales ; si- 
nister minor ; medius dextro sublongior. 
Animal czerulescente-nigrum. 
Shell ventricose, of a deep brown-chestnut colour. Peritreme 
whitish. Aperture, with eight teeth, varying in size; the three 
anterior, unequal; the left one shortest; the middle one longest ; 
the left tooth thicker than any of the rest: the right tooth 
very small, tuberculiform ; the three hinder teeth unequal ; 
the left smallest ; the middle rather longer than the right one. 
The ninth tooth in var. (3. is tuberculiform, and is situated 
between the middle anterior and the left anterior tooth. 
I observed but one specimen of this shell in the collection of 
Montagu, who had not distinguished it from the following spe- 
cies ; and have since received living specimens from Mr. J. E. 
Gray, who found them on Isolepis fluitans, in a marsh near 
Wimbledon Common. 
Animal bluish-black. Height one-tenth of an inch. 
2. VERTIGO VULGARIS. 
V. testa subteretiuscula, apertura tenuiter sinuata, 5-dentata : 
dentibus tribus anticis; 1 sinistro et 1 postico, centrali. 
Testa fusco-brunnea. Peritrema pallidé subroseum aut albi- 
dum. Apertura dentibus anticis ineequalibus ; medio longiore : 
dente sinistro aliis crassiore. 
Habitat in paludibus. 
Shell fuscous-brown, somewhat rounded, its aperture slightly 
sinuated, with five teeth; three anterior ; of these, the middle 
