Balea. mollusca. pulmonifera. 
271 
Gen. XXVI. BALEA. — Tentacula four ; pillar simple. 
98. B. perversa. — Whorls eight or nine, tapering, rounded. 
Buccinum alterum pellucidum subflavum, List. An. Ang. 124. — Turbo 
perversus, Mont. Test. Brit. 355. t. xi. f. 12. — Pupa fragiHs, Drap. 
MoU. 68. — In moss at the roots of trees. 
Length nearly half an inch, translucent, with minute sharp lines of growth ; 
apex blunt ; whorls tapering regularly ; mouth rounded anteally, becoming 
narrow at the retral external angle ; peristome thin on the body, with one 
tooth, slightly reflected at the pillar, forming behind a small cavity. Ac- 
cording to Lister, the individuals pair in March, a smaller with a larger. — 
This genus, instituted by Mr Prideaux, has been' described by Mr Gray, 
Zool. Journ. No. i. 61. 
Gen. XXVII. CLAUSILIA.— Tentacula four ; piUar with 
an attached pedunculated testaceous scale, for closing the 
aperture. 
99. C. bidens.-^Whorh eleven, smooth, glossy ; the pillar- 
scale emarginate. 
Buccinum exiguum. List. Conch, t. xli. large fig. — Helix bidens. Mull. 
Verm. 116. — Turbo bidens, Penn. Brit. Zool. iv. 131. — T. laminatus, 
Mont. Test. Brit. 359. t. xi. f. 4. — Cl. bidens, Drap. Moll. 68 — Eng- 
land. 
Length about f ths of an inch ; whorls slightly rounded, and Avell defined 
by the separating line ; aperture rounded, sub quadrangular ; peristome ad- 
hering to the body, slightly reflected at the pillar ; two conspicuous teeth or 
folds on the body, lip, and three others, concealed within the aperture. 
100. C. perversa. — Whorls twelve, striated, aperture entire, 
rounded; pillar- scale entire. 
Buccinum pullum ^opacum ore compresso circiter denis spiris fastigia- 
tum. List. An. Ang. 123. Conch, t. xli. f. 39 — Helix perversa. Mull. 
Verm. 118. — Turbo bidens, Mont. Test. Brit. 357 — Clausilla rugosa, 
Drap. Moll. 73 — Turbo nigricans, Maton and Rackett, Linn, Trans, 
viii. 180. — In walls and trees, common. 
Length about half an inch, somewhat swollen in the middle, of a brown colour. 
Whorls rounded at first, becoming more flat towards the mouth ; lines of 
growth distinct ; aperture detached from the body-whorl, rounded anteally, 
narrow retrally, with a ridge on the body-whorl behind ; peristome white, 
reflected, with two teeth on the pillar-lip ; pillar-scale entire.— Judging from 
specimens obligingly sent me by Mr MiUar, I am inclined to consider his 
Turbo Everetti (Annals of Phil. xix. 377-) as belonging to this species. 
101. C. hiplicata. — Whorls twelve or thirteen, aperture en- 
tire, compressed ; piUar-scale entire. 
Turbo bip. Mont. Test. Brit. 316. t. ii. f. 5 — In Wiltshire. 
Ijength about fths of an inch, brown, with distinct lines of growth ; whorls 
slightly rounded ; aperture narrow at both ends ; peristome entire, detached, 
slightly reflected, with two approaching teeth on the body-lip. This species, 
specimens of which were sent me by Mr Montagu, does not seem to corre- 
spond with any of those described by Draparnaud. — The Helioe papillaris of 
