32 
MOLLUSCA. 
Nautilus. 
duce an undulated appearance in its edges ; the aperture is 
long, and faces the spiral part. 
Found in the Gray Chalk Marie at Harasey, and is very 
rare. 
3. S. equalis. —The Equal Scaphite, pi. XXII. fig. 7> 8, 
9, and 15. 
Scophites equalis . Sower by, Min. Conch. I. p. 53, pi. 18, 
fig. 1, 2, 3. Fleming, Brit. An. p. 249. Buckland, Geology 
and Mineralogy Considered, II. p. 66, pi. 44, fig. 15, 16. 
Involute, umbilicate; inner volutions concealed; inner 
parts of the sides with projecting distant ribs ; these extend 
to nearly the centre, where they are rounded; smaller ribs 
equal to two to each of the larger ribs; these pass over the 
greatly enlarged ventricose, and thickened ambit; aperture 
incurved ; the outer coating preserves part of the pearlaceous 
lustre of the original shell. Length about an inch. 
Fig. 7? side view; 9, a transverse section of the 
portions, exhibiting the arrangement of the lobes and saddles ; 
from which it will be observed they are the same as in the 
genus Ammonites , the siphuncle also is seen on the dorsal 
margin at a ; 8 exhibits the front, with the volution central ; 
15 is a section through one of the concamerations, exhibiting 
part of the undulations. 
Found in the Green Sand, at Yeovil, by Dr Leach. 
4. S. obliquus. —The Oblique Scaphite, pi. XXII. fig. 10, 
11, 12, 13. 
Scaphiles obliquus . Sowerby, Min. Conch. I. p. 54, pi. 18, 
fig. 4, 5, 6, 7. Fleming, Brit. An. p. 249. 
Obliquely involute; umbilicate; inner volutions concealed; 
sides transversely striate, which, after reaching the centre, 
become doubly or triply furcate, and pass over the rounded 
ambit, and meet with those on the opposite side. Length 
nearly an inch ; width about three quarters, thickest part half 
an inch. 
M iss Bonnet possesses a specimen from the Hard Chalk, 
Warminster, which measures an inch and a quarter in 
length. 
This shell will readily be distinguished by the obliquity of 
its curve, the fineness of its stria?, and the great incurvation 
of the last volution. 
Found in the Marie Pit, Lewis, Ilamsey, by Dr Mantel!, 
and is not met with in the Chalk at Brighton. 
Fig. 12 exhibits the obliquity of the spire in a front view of 
the shell; fig. 13 is a segment shewing the concamerations. 
5. S. tuberculatus.— The Tubcrculated Scaphite, pi. 
XXII. fig. 6 and 14. 
Scaphites luherculalus. Parkinson, Organic Remains, III. 
p. 145, pi. 10, fig. 10, 11. 
Involute, umbilicate ; inner volutions concealed ; from the 
inner margin a series of wide set ribs emanate, the six outer 
ones, on reaching the centre, terminate in a large and pro¬ 
duced tubercle, and arc met by numerous small rounded ribs, 
which pass over the ambit; in the remaining portion of the 
volution, the large ribs cross the sides entirely, and passing 
over the somewhat rounded ambit, proceed continuously to 
the inner margins on the opposite side; numerous small 
round ribs intervene between these, and terminate .about the 
centre of the sides ; at the termination of the reflected part at 
the mouth, a border is formed by the edge of a regularly 
rounded groove. Length an inch. 
Found in Dorsetshire, as also in the Chalk Pit, Brighton, 
by Mr Herbert. 
Family II.— Nautilacea. 
Shell discoidal, with a central spire, and short cells, 
which do not extend from the centre to the circum¬ 
ference. 
Genus VII.—NAUTILUS.— Linnaeus. 
Shcdl suborbicular, multilocular; convolute, with con¬ 
tiguous volutions, and simple partitions; septa transverse; 
and externally concave, perforated in the disk; margins 
entire; aperture ample. 
1. N. tetragonis. —The Quadrangular Nautilus, pi. XXII. 
fig. 16. 
Nautilus tetragonis. Phillips, Geology of Yorkshire, II. 
P- 
Discoidal, flattened, with tetragonal volutions; ambit 
slightly concave, and provided with a small spiral ridge 
within the angles, sides crossed by sharp bent striae, which 
rise into ridges, or plaits on the edges ; septa outwardly con¬ 
cave. 
Found at Kulkeagh and Bolland, Queers County, Ireland; 
and also in Northumberland. 
2. N. inequalis* — The Unequal Nautilus, pi. XXII. 
fig. 17. 
Nautilus inequalis. Sowerby, Min. Conch. I. p. 88, pi. 
40, lower figures. Fleming, Brit. An. p. 229. 
Spheroidal, umbilicate; aperture nearly round, and 
obscurely trilobate, embracing the volutions, and nearly 
equal to one-half the diameter of the shell in length, and 
about the same in width; septa but slightly curved, remote 
in the inner volutions, and in the outer ones rather con¬ 
tiguous ; siphunculus situate near the inner margin of the 
septum* 
It is rather singular that the septa should be closer in the 
outer volutions than in the inner ones, where the distance is 
equal to their own length. 
Found at Folkstone by Mr Gibbs. 
3. N. multica rinat us.—The Many-Keeled Nautilus, pi. 
XXII. fig. 18. 
Nautilus multica rinatus. Sowerby, Min. Conch. V. p. 
129 , pi. 482, fig. 1, 2. Phillips, Geology of Yorkshire, II. 
p. 232. 
Discoidal, subglobose, umbilicate ; umbilicus large, deep, 
and angular, with an angular edge, in which the sides 
of the inner volutions are half exposed ; ambit compressed, 
very broad, and flattened, with its centre plain, and provided 
on each side with four sharp carinae, exclusive of the one 
which invests the margins of the umbilicus. 
Found in the Black Rock, at Cork, Ireland, where it is 
very rare. 
4. N. cahiniferus.—T he Keeled Ammonite, pi. XXII. 
fig. 19. 
Nautilus cariniferus. Sowerby, Min. Conch. V. p. 130, 
pi. 182, fig. 3. 4. Phillips, Geology of Yorkshire, II. p.232, 
pi. 17, fig. 19* 
Discoidal, subglobose, umbilicate; inner volutions half 
exposed within the very large, deep, and sharp margined 
