36 
MOLLUSCA. 
not tumid ; the side of the columella is almost concave. The shell will 
not receive the entii’e animal, and it might almost be considered as a 
large-shelled Tcstacella. Its inferior tentacula are very small, and it 
lives on the plants and shrubs which line the banks of rivulets, a cir- 
cumstance which has caused the genus to be considered as amphi- 
bious* * * § . 
It is necessary to separate from the genus Turbo of Linn, and refer 
to the genus of terrestrial Helices the following : 
Clausilia, Draj). 
The shell is long, slender, and pointed, the last whorl, in the adult, 
narrowed, compressed, slightly detached, and terminated by a com- 
plete aperture with a tumid margin, frequently dentated or furnished 
with laminae. In the contraction of the last whorl Ave usually find a 
little plate bent into an S, tlie use of which to the living animal is 
unknoAvn. 
The species are very small, living in mosses at the foot of 
trees, &c. A great many of them are reversedf. 
It is also necessary to separate from the Bulla of Linn, and place 
here 
Achatina, Lam. 
In Avhich the aperture of the oval or oblong shell is higher than it is 
broad, as in the Bulimi, but it Avants the tumid margin ; the ex- 
tremity of the columella also is truncated, the first indication of the 
emarginations Avhich Ave shall find in so many marine Gasteropoda. 
These Achatinee are large Helices, Avhich devour trees and shrubs in 
hot countries |. 
Montfort distinguishes those, in the last Avhorl of Avhich Ave find a 
callus or peculiar thickening, — Lirjuns, Montf. || ; this Avhorl is propor- 
tionably loAver in them than in the others : 
And those in Avhich the extremity of the columella is curved to- 
Avards the inside of the aperture, — Polyphemus, Montf.§ ; the last 
Avhorl is higher. The 
* Succinea amphibia, Drap., IV, 22, 23 (Helix putris, L.) ; — S. oblonga, Ib., 24. 
— Tbe geneva Coculoha'dr a, Ft^russ., Lucina, Oken, Tassade, Huder, cor- 
respond to the Succinefe. M. Delamark at first styled them Amphibulimi. The 
Amphibulime encapuchonne, Lam., Ann. du Mus. VI, Iv, 1, may also form a Testa- 
cella. 
f Turbo perversits, L., List., 41, 39 ; — T. bidens, Gm., Drap., IV. 5, 7 ; — T. pa- 
pillaris, Gm., Drap., Ib., 13 ; and the other Clausiliae of Drap., figured on the same 
plate ; — Bulimus relusus, Oliv., Voy., XA"II, 2 ; — Bui. injlatus, Ib., 3 ; — Bui. teres, 
Ib., 6 ; — Bui. torticollis, Ib., 4, a, b ; — Turbo tridens, L., Chemn., IX, xii, 957 ; — 
Clausilia collaris, Feruss., List., 20, 16. 
+ Bulla zebra, L. Chemn., IX, ciii. 875, 876: exviii, 1014 — 1016 ; — Bidla 
achatina, Ib., 1012, 1013 ; — Bulla purpurea, Ib., 1018 ; — Bulla dominicensis. Id., 
CXA'II, 1011 : — Bulla stercus pulicum, CXX, 1026, 1027 ; — Bulla flammea. Id., 
CXIX, 1021 — 1025 ; — Tielix tenera, Gm., Ib., 1028, 1030 ; — Bulimus bicarinutus, 
Brug., List., 37 ; — Melanie buccinotde, Oliv., A oy., XVII, 8. 
i| Bulla virginea, L., Chemn., IX, cxvii, .1000, 1003 ; X, clxxiii, 1682 — 3. 
§ Bulimus glans, Brug., Chemn., IX, cxvii, 1009, 1010. 
