Euompiialus. 
MOLLUSCA. 
81 
12. C. depresses —The Depressed Cirrus, pi. XLI. fig. 
29, 30. 
Cirrus depressus* Mantell, Geo. of Sussex, p. 195, pi. 18, 
fig. 18 and 22. Sowcrby, Min. Conch. V. p. 35, pi. 428, fig. 3. 
Phillips, Geo. of Yorkshire, I. p. 112, pi. 6, fig. 12. 
Shell depressed, subdiscoidal; volutions separated by a deep, 
wide, canaliculate, angular suture, a small portion of each only 
being visible, their internal sides regularly convex, the apical 
one hardly elevated above the body volution; aperture obtusely 
angular; whole surface covered with strong spiral striae. 
This species differs from C. perspcclivus , in the spire being hardly 
elevated above the margin of the body volution, which renders the 
umbilicus shallow. 
Found in the Upper or Flinty Chalk, near Lewis, Suffolk; 
Kent, and Wiltshire; also in the Kelloways Rock at Hackness 
and Scarborough. 
13. C. perspectives —The Perspective Cirrus, pi. XLI. 
fig. 31 and 33. 
Cirrus perspective. Mantell, Geo. of Sussex, p. 194, pi. 
18, fig. 12 and 21. Sowcrby, Min. Conch. V. p. 35, pi. 428, 
fig. 1, 2. 
Shell obtusely conical, not quite so high as wide; volutions 
six or seven, convex, a little square externally; base rather 
flattened; umbilicus wide and deep, exposing about a third of 
the width of the inner and convex edges of the volutions; aper¬ 
ture transversely oblong; surface covered with fine spiral strife; 
inner surface pearlaceous. 
Found in the Upper Chalk of the South Downs, Sussex; 
Kent, and Wiltshire; and sparingly in the Lower Chalk. 
14. C. carinatus, —The Keeled Cirrus, pi. XLI. fig. 32. 
Cirrus carinatus . Sowcrby, Min. Conch. Y. p. 36, pi. 429, 
fig. 3, 4. 
Shell discoidal, smooth,; spire depressed, consisting of three 
or four ventricosc volutions, obtusely carinated, and convex 
below; umbilicus large and deep; aperture transverse and sub- 
ovate. 
Found at Lakehampton Hill, near Cheltenham. 
15. C. granelates. —The Granulated Cirrus. 
Cirrus granulatus. Mantell, Geo. of Sussex, p. 195. 
Conical; with five or six obscurely quadrangular volutions, 
depressed on their upper and under surface, broad and slightly 
convex on the outer margin ; ornamented with very regular, 
granulated, or moniliform stria). 
bound in the Lower Chalk, near Lewis, by Dr. Mantell. 
We have never seen either a figure or specimen of this species. 
Genus XXXVII.—EUOMPIIALUS.— Sowerby. 
Orbicular, conical; spire short, with three or four 
volutions, imbricated above, and smooth below; aperture 
of a round. polygonal form; umbilicus large, penetrating 
to the apex of the shell. 
The shells of this genus are known only in a fossil 
state; the species strongly resemble those of Delphinula , 
the volutions, however, of that genus increase in size 
much more rapidly than those of Euompiialus. 
1. E. calyx. —The Flower-cup Euompiialus, pi. XLII. 
fig. 23. 
Euompiialus calyx. Phillips, Geo. of Yorkshire, II. p. 225, 
pi. 13, fig. 3. 
Shell depressed; with three or four volutions, the apical one 
hardly elevated above the others; external margin of the volu¬ 
tions provided with a narrow carina, which forms a separating 
internal suture to the lower portions of all the volutions; base 
of the shell deeply concave. 
Found in the Mountain Limestone at Bolland. 
2. E. angulatus. —The Angular Euompiialus, pi. XLII. 
fig. 26, 27. 
Euompiialus angulatus . Sowcrby, Min. Conch. I. p. 114, 
pi. 52, fig. 3. 
Shell with three much depressed volutions, and a series of 
three spiral ribs on their upper surface, the lower one on the 
extreme edge of the volution; the whole surface being covered 
with numerous longitudinal, subimbricated, distant, rough, irre¬ 
gular stria;; base with five concentric, somewhat rounded ribs, 
which are crossed by remote, indistinct stria), diverging from 
the centre; these concentric ridges on the base form five 
sharpish angles, and those of the spire three more acute angles, 
on the margin of the outer lip ; aperture obscurely octangular. 
Found in Limestone at Colebrook Dale. 
3. E. funatus —The Corded Euompiialus, pi. XLII. fig. 
24, 25. 
Euompiialus funatus. Sowerby, Min. Conch. V. p. 71, pi. 
450, fig. 1, 2. Skeneafunata y Fleming, Brit. An. p. 314. 
Shell subconic, very short, consisting of three depressed volu¬ 
tions; provided with a series of narrow, rounded, thread-like, 
spiral ribs, crossed by numerous, transverse, thin stria); umbili¬ 
cus rather small; base with several concentric ridges. 
This species is distinguished from E. discors , by having ribs on 
its base, and in the transverse strke being much finer, closer, and 
less rough in appearance, particularly those upon the upper surface. 
Found in the Limestone at Dudley. 
4. E. pentangelates. —The Five-angled Euompiialus, pi. 
XLII. fig. 28, 29. 
Euomphalus pentangulatus . Sowerby, Min. Conch. I. p. 
97, pi. 45, fig. 1, 2. Phillips, Geo. of Yorkshire, II. p.225, 
pi. 13, fig. 13. Ib., Treatise on Geology, I. p. 163, fig. 13. 
Skenea perangulatus y Fleming, Brit. An. p. 314. 
Shell consisting of five or six depressed, almost entirely 
exposed, volutions; the spire being somewhat sunk below the 
body, or external volution; the volutions provided with an 
acute, elevated, central, spiral carina, or rib, on the superior 
portion of the shell, extending from the centre of the aperture 
to the apical convolution; the base with a slightly angular, 
nearly obsolete, concentric ridge; the whole crossed by some¬ 
what fine, sharp, elevated striae; aperture obscurely pentangular, 
somewhat rounded externally; the underside deeply and widely 
umbilicated; internal cavity divided into chambers, by imperfo¬ 
rate septa. 
The shell appears to he thin. 
Found in the Carboniferous Limestone of Ireland. 
5. E. catillus. —The Little-dish Euomphalus, pi. XLII. 
fig. 30, 31. 
Euomphalus catillus. Sowerby, Min. Conch. I. p. 98, pi. 
45, fig. 3, 4. Phillips, Geo. of Yorkshire, II. p. 225, pi. 13, 
