82 
MOLLUSCA. 
SCALARIA. 
fig. 1, 2. Helix catillus , Martin, Petrificata Derbiensia. Par¬ 
kinson, Org. Rem. III. pi. G, fig. 1 and 3. Skeneci catellus , 
Fleming, Brit. An. p. 314. 
Shell depressed, consisting of four or five almost entirely 
exposed volutions, with a prominent central carina, or ridge, 
both above and below, and one side deeply umbilicate, in the 
form of a hollow cone; aperture sub triangular, taking the sharp 
form of both the carina?, the sides next the body being longest. 
Distinguished from E. pentangulatus. , by the keel on its inferior sur¬ 
face. 
Found in the Carboniferous and Mountain Limestone. 
G. E. discors.— The Discordant Euomphalus, pi. XLII. 
fig. 32, 33. 
Euomphalus discors . Sowerby, Min. Conch. I. p. 113, pi. 
52, fig. 1. Delpliinula discors , Fleming, Brit. An. p. 313. 
Shell subdepressed; with three or four volutions, the larger 
or body one subimbricated the whole surface above, covered 
with wide-set, undulating, transverse stria?, most conspicuous in 
passing over the spiral carina?, and producing a cord-like appear¬ 
ance ; and with five spiral, rather prominent, rounded ribs on 
the superior portion of the volutions, which rise a little above 
the body, and the two superior ones terminating in a flattened, 
truncated surface; base of the body volution smooth, large, and 
rounded; the other volutions small, with a deeply umbilicated 
centre. 
Found in the Carboniferous Limestone, Colebrook Dale. 
7. E. uugos us_The Wrinkled Euomphalus, pi. XLII. fig. 
34, 35. 
Euomphalus rugosus. Sowerby, Min. Conch. I. p. 113, pi. 
52, fig. 2. Delpliinula rvgosa y Fleming, Brit. An. p. 313. 
Shell with three or four depressed volutions; with four spiral 
ribs above, crossed by oblique, wide-set, undulating strong stria?, 
which are stronger as they pass over the ribs, the lower one of 
which forms an acutely carinated margin to the body volution; 
under surface of the body with strong, irregular, transversely 
curved plaits, and deeply umbilicated; aperture subovate, 
acutely pointed at the carina, and where it forms a junction 
with the body. 
This species will be easily recognised from the E. discors , by its 
plaited under surface. 
Found in the Carboniferous Limestone of Colebrook Dale. 
8. E. cristatus. —The Crested Euomphalus, pi. XLII. 
fig. 3G. 
Euomphalus cristatus . Phillips, Geo. of Yorkshire, II. p. 
225, pi. 13, fig. 5. 
Shell with three, widely separated, rather smooth volutions, 
nearly equally rounded on both sides; the exterior margin pro¬ 
vided with a series of alternately large and somewhat smaller, 
conical, recurved, rather sharp tooth-like processes, which 
extend to the inner volution. 
Found in the Mountain Limestone at Bolland. 
9. E. nodosus. —The Knotty Euomphalus, pi. XLII. fig. 
37, 38. 
Euomphalus nodosus. Sowerby, Min. Conch. I. p. 99, pi. 
46, fig. 1, 2. Delpliinula nodosa , Fleming, Brit. An. p. 313. 
Shell depressed, rather smooth, consisting of four volutions; 
the upper side with a nearly central, elevated, rounded spiral 
ridge; under surface with a central, spiral series of ovate, rather 
large, nodular elevations; these continue in the lower side of 
all the volutions, but are only here visible, as the volutions 
conceal the external sides of each other to that extent; aper¬ 
ture nearly orbicular, the side next the body being a little 
square; under surface forming a cup-shaped hollow cone. 
Found in the Carboniferous Limestone of Derbyshire. 
10. E. bifrons— The Double-fronted Euomphalus, pi. 
XLII. fig. 39. 
Euomphalus hifrons. Phillips, Geo. of Yorkshire, II. p. 
225, pi. 13, fig. 4. 
Shell with three rounded volutions; with a spiral series of 
nearly orbicular, prominent tubercles above, and obtusely angu- 
lated and umbilicated below. 
Found in the Mountain Limestone at Bolland. 
11 . E. pugilis.— The Champion Euomphalus. 
Euomphalus pugilis. Phillips, Geo. of Yorkshire, p. 225. 
Volutions tuberculate on both sides, which distinguishes it 
from the E. bifrous, to which it otherwire bears a strong 
resemblance. 
12. E. coronatus. —The Crowned Euomphalus, pi. XLII. 
fig. 20, 21, 22. 
Euomphalus coronatus. Sowerby, Min. Conch. V. p. 71, 
pi. 450, fig. 3. 
Shell discoidal, quite flat above, the volutions being ranged 
on the same plain; the margin provided with a carina of broad, 
flat, slightly pointed, sharp spines; volutions below, rounded, 
and deeply concave, terminating in a central umbilicus. 
Found at Audi fie. 
Genus XXXVIII.—SCALARIA.— Lamarck. 
Shell turreted, elongated, with gibbous, deeply defined 
volutions, quite apart in some species, provided with 
longitudinal, oblique, acute ribs, which in some instances 
are so thickened as to become distinctly varicose, in one 
or two instances, however, they are barely elevated 
above the surface of the shell; aperture nearly orbicular, 
but generally somewhat longer than broad, its margin 
thickened all round and reflected, and more so in such 
species where the volutions are separated; on one side, 
the lower part of the columella assumes the appearance 
of an indistinct canal, which is more conspicuous in some 
species than in others; operculum thin, and cornuous. 
1 . S. frondosa.— The Leafy Scalaria, pi. XLII. fig. 1. 
Scalaria frondosa. Sowerby, Min. Conch. VI. p. 149, pi. 
577, fig. L 
Shell conical, turreted, elongated; with seven or eight deeply 
divided, distinct, smooth volutions; each covered with about 
twelve longitudinal, membranaceous, very thin, recurved, very 
uniform ribs, with their superior portions extending above the 
upper margins of the volutions in the form of concave spines. 
This beautiful species is found in the SuHoik Crag. 
2. S. foliage a— The Foliated Scalaria, pi. XLII. fig. 2. 
Scalaria foliacea. Sowerby, Min. Conch. IV. p. 125, pi. 
390, fig. 2. Fleming, Brit. An. p. 312. G. B. Sowerby, 
Genera of Shells, No. 11. 
