( 35 ) 
DIVISION XVII. 
GENERA. 
4. Trocnrus. (1) Lam. 
Conical; mouth more or Base flat or concave. 
less quadrangular, in an 
oblique plane to the axis 
of the shell; operculum 
thin, horny, orbicular. 
a The columella, in 
outer lip. Pl. 9, fig. 7 
fig. 4 
the columella. 
Not umbilicate. 
spiral canal, 
f Turreted. 
g No projection to the columella. 
h Flattened; the exterior angle edged. 
i Flattened; the lips rounded. 
Umbilicate. 
£ Columella embattled lengthwise. 
2. Crrrites. Sowerby, 
Conical ; whorls united. 
Pl? 9) fig. 4. 
No columella: umbi- 
licus funnel-shaped. 
3. Sorarnium. (2) Lam. 
Spire like a dilated cone. 
PI 9, fig. 44. 
A very large umbili- 
cus, hollowing out the 
base. 
4, Evompuatires. Sow- 
erby. 
Rolled almost in the Concave or largely um- 
same plane, depressed bilicate underneath. 
above. PI. 9, fig. 18, 19. 
5. [antarna. Lanz. 
Subglobulous, horizon- 
tally volute ; no opercu- 
lum. Pl. 9, fig. 26. 
Columella prolonged 
eyond the mouth. 
GONYOSTOMATA 
Marine, or inhabiting 
the brackish ponts com- 
municating with the sea. 
Y Animal, p. 66. 
the form of a concave arch, continued with the 
6 Calear, Montf. Flattened; lip sharp, like the rowel of a spur. Pl. 9, 
ec With a small prominence, or vestige of a tooth, towards the base of 
d Mouth much broader than long; base concave. Pl. 9, fig. 9. 
e Mouth much broader than long; and the columella in the form of a 
k Columella with a prominence towards the base. 
In the Chalk Marle, 
under Oolite, and Der- 
byshire - Peak Lime- 
Stone. 
Marine. 
V. Animal, p. 66. 
In the LimestoneShale ; 
in the 4st or Upper 
Grey and in the Peak 
Limestone of Derby 
shire. 
Marine. 
Mediterranean. 
tralasia. 
A floating shell. 
VY. Animal, p. 67. 
Aus- 
(1) Foss inthe London Clay ; Crag Marl; Under Oolite; Blue Lias 3; at Grignon; 
fo) 
near Pont Chartrain; Longjumeau. The Trochus agglutinaus, Pl. 9, fig. 8, is re- 
markable for its habit of agglutinating to, and even of incorporating with, its 
shell, during the growth, small pebbles, fragments of other shells, sand, etc. ete. 
It often covers the umbilicus with a testaceous plate. A fossil variety of this cu- 
rious shell, which inhabits the seas of South America, is found at Griznon, 
(2) Foss, in the London Clay; Purbeck Limestone; at Grignon, z 
