78 
horny, more or less spiral, and variable in form; outer 
side flat; inner side furnished with an irregular, nearly 
lateral tubercle. 
1. S. discoideum —The Discoidal Solarium, pi. XLI. fig. 
1 , 2 . 
Solarium discoideum . Sowerby, Min. Conch. I. p. 36, pi. 
11, upper right hand figs. Fleming, Brit. An. p. 325. 
Shell discoidal; spire consisting of five or six volutions, some¬ 
what acuminated at the apex; outer edge of the body volution 
provided with a very sharp carina, within which, on the base, is 
a shallow canal; the upper margin broad, considerably undu¬ 
lated, and spirally striated, but becoming obsolete towards the 
spire; umbilicus deep, rounded, and transversely wrinkled; 
aperture rhomboidal, obliquely elliptical, and a little pointed at 
both ends; outer lip acute at the margin. 
Found in the London Clay at Barton Cliff, Hampshire. 
2. S. canaliculatum.—T he Canaled Solarium, pi. XLI. 
fig. 3, 4. 
Solarium canaliculatum . Sowerby, Min. Conch. VI. p. 43, 
pi. 524, fig. 1. Fleming, Brit. An. p. 326. Lamarck, Env. de 
Paris, p. 104. Turbo , Brander, Foss. Hant. p. 10, pi. 1, fig. 7, 
8 . Trockus canaliculatus , Brocchi, II. p. 359. 
Shell discoidal, convex; body provided with a prominent 
crenated margin, both above and below with numerous spiral, 
unequal, granulated lines; umbilicus furrowed, and crenated 
internally ; aperture quite circular. 
Found plentifully in the London Clay at Barton Cliff. 
3. S. conoideum—T he Conical Solarium, pi. XLI. fig. 5, 6. 
Solarium conoideum. Sowerby, Min. Conch. I. p. 36, pi. 
11, three middle figs. Ib., Geo. Trans. IV. 2nd series, p. 336, 
pi. 11, fig. 14. Fleming, Brit. An. p. 325. 
Shell conical, its height being equal to the diameter of the 
base, smooth; volutions slightly depressed, or concave in the 
middle, and covered with decussating stria?, producing rows of 
granules; umbilicus deep and narrow, with its inner spiral ridges 
crenated; aperture rhomboidal, or nearly quadrangular. 
Found in the Upper Oolite at Portland, and the Galt, near 
Folkstonc, Kent. 
4. S. Sowerbyii. —Sowerby’s Solarium, pi. XLI. fig. 7, 8. 
Solarium patulum. Sowerby, Min. Conch. I. p. 35, pi. 11, 
lower left hand figs. 
Shell almost discoidal; spire much depressed; umbilicus 
large, with nearly obsolete crcnulations on its margin, except in 
its interior, where it is striated. 
Found in the London Clay at Ilighgate Hill. 
5. S. plicatum.—T he Plicated Solarium, pi. XLI. fig. 
10 , 11 . 
Solarium plicatum. Sowerby, Min. Conch. VI. p. 44, pi. 
524, fig. 2. Fleming, Brit. An. p. 326. Lamarck, Env. de 
Paris, p. 104. 
Shell convex, subdiscoidal; upper surface longitudinally 
wrinkled, ornamented with three or four very narrow, deep 
spiral sulci; base with a small umbilicus, surrounded by a pro¬ 
duced, crenated ridge, which descends into the cavity, and 
sometimes half closes it, and in other instances it is left more 
open; five or six concentric strong, or unequal sulci; aperture 
nearly orbicular. 
Found in the London Clay at Barton Cliff. 
Solarium. 
6. S. patulum* —The Spreading Solarium, pi. XLI. fig. 
12, 13. 
Solarium patulum . Sowerby, Min. Conch. I. p. 35, pi. 11, 
lower right hand figs. Lamarck, Ann. du Mus. IV. p. 53, pi. 
35, fig. 3. Fleming, Brit. An. p. 325. 
Shell depressed, discoidal, smooth; volutions defined by a 
crenulated carina, which is strong and produced on the body; 
umbilicus wide, with a beautifully crenulated margin, which is 
surrounded by a border of small denticles; surface provided 
with fine longitudinal striae; base with divergent stria?. 
Found in the Dark-coloured London Clay at Highgate. 
7. S. tabulatum. —The Boarded Solarium, pi. XLI. fig. 
14. 
Solarium tabulatum. Phillips, Geo. of Yorkshire, I. p. 94, 
pi. 2, fig. 36. 
Shell pyramidal, subturreted; the volutions obliquely flat¬ 
tened above, with a carinatcd margin on their upper and lower 
edges, and terminating in a somewhat acute apex; surface 
covered with wide-set, longitudinal, strong striae; base flat; 
umbilicus small. 
Found in the Speeton Clay at Spccton. 
8. S. Calix. —The Chalice Solarium, pi. XLI. fig. 15. 
Solarium Calix. Phillips, Geo. of Yorkshire, I. p. 129, pi. 
11, fig. 30. 
Shell pyramidal, turreted; body large; spire small, consisting 
of four rapidly diminishing, flat-sided volutions, bounded above 
and below by a slightly crenulated, rounded, projecting spiral 
band; base rather flat, furnished with a wide, expanding um¬ 
bilicus ; aperture subquadrangular. 
Found in the Blue Wick of the Inferior Oolite, Cold Moor, 
by Mr. Bean of Scarborough. 
9. S. ornatum. —The Adorned Solarium, pi. XXXVII.* 
fig. 39. 
Solarium ornatum . Sowerby, Geo. Trans. IV. 2nd series, 
p. 336, pi. 11, fig. 13. 
Shell discoidal; with seven or eight volutions, the three 
lower ones produced in the middle, and sloping towards each 
side; the other volutions, which are very small, and rising 
abruptly in a conical form, terminate in an acute apex; the 
three upper ones smooth, all the others ornamented above by 
obtuse, smooth radiating ribs, with a sharp carina bounding 
the body volution; near the margin, both above and below, 
beset with granules, placed in quincunx order; aperture rhom¬ 
boidal. 
Found by Dr. Fitton in the Upper Green Sand, Isle of 
Wight. 
FAMILY II.—SCALARIDES. 
Shell devoid of plaits or folds on the columella; mar¬ 
gins of the aperture united in a circular form. 
Genus XXXV— RI SS OA.— Freminville. 
Shell oblong, turreted, considerably acuminated; spire 
consisting of numerous volutions; aperture orbicular, or 
MOLLUSCA. 
