CLASS FIRST. 
UNIVALVE TESTACEOUS MOLLUSCA. 
ORDER L— CEPHALOPODA. 
Hoad of the animal emanating from a bag-shaped mantle, and 
sun'onnded by inarticidated ai'ms, provided with a sneker, and in- 
vestmg the mouth ; two sessile eyes ; mouth furnished with two 
horny mandibles ; three hearts j the sexes in separate individuals. 
Family I. — Nautilacea. 
Shell discoid, with a central si)ire, the cells short, and not ox- 
tendin" from the centre to the circiunference. 
Genus 1. — Nautilus . — Linneeus 
Shell discoid, spiral, multilocular, with simple partitions ; volu- 
tions contiguous, the last or body-one enveloping the rest ; the 
septa transverse, and externally concave, perforated in the disc ; 
margins entire. ' 
1. A’’. Becarii, pi. I, f. 11. — First Edition, pi. 62, f. 11 ; Montagu’s Testacea 
Britannicn, p. 186, pi. 18, f. 4 ; Walker’s Minute Shells, f. 63. 
Shell with four or five volutions, the joints deeply sulcated; ten septa in 
the first whorl ; convex above, and flat beneath, the markings less distinct, 
aportui-e turned downwards, and not clasping the body volution ; siphon 
small, and usually situate in the convex front ; covered with a brown epi- 
dermis, but white when divested of its skin ; in which condition, if the 
animal is alive, it is of .a crimson colour, size not a lino. Found on the 
Devonshire coast, and in tlie Frith of Forth, adhering to the Fmm vesiculostis, 
the roots of Algas, and on Oyster shells. 
2. N. Becarii perversm, pi. I, f. 12. — First Edition, pi. 52, f. 12 ; Montagu, 
p. 187, pi. 18, f. 6; Walker, f. 64. 
Shell with the volutions reversed, and agreeing in ever)'' respect with the 
description of Nautilus Becarii, It cannot be considered as a htsus, because 
it is nearly as plentiful as Cecarii. 
3. N. crassulus, pi. I, f. 5. — First Edition, pi. 51, f. 5 ; Montagu, p. 191, 
pi. 18, f. 2 ; Walker, f. 70. 
Shell strong, spiral, with numerous close-set elevated septa ; sides com- 
pressed, similar, doubly umbilicated, within which, part of the interior 
volution is seen ; aperture placed a little oblique, scarcely clasping the body, 
and provided with a siphon ; colour cream white, sometimes brownish; size 
not more than half a line. Found at Reculver ; very rare. 
4. N. umhilieaiulus, pi. I, f. 8. — First Edition, pi. 52, f. 8; Montagu, p. 191, 
pi. 18, f. 1 ; Walker, f. 69. 
Shell spiral, compressed, umbilicated on both sides, subpolluced, with nine 
or ten raised septa ; aperture clasping the body volution almost equally on 
both sides, the interior volutions being hid. The most minute of all the 
Nautili, about the fourth of a line in size. 
5. N. depnmulus, pi. I, f. 3. — First Edition, pi. 52, f. 3 ; Montagu, p. 190, 
pi. 18, f. 9 ; Walker, f. 68. 
Shell spiral, with about nine visible septa, radiating from the centre in 
curved lines, distinguished by their opacity, but not embossed ; sides similar ; 
in the centre is a smf*ll pellucid spot, which may bo mistaken for an umbi- 
licus ; the aperture does not clasp the body so much as that of the N. calcar, 
from which it also differs in being much more compressed, having no carina, 
and in the concamerations being more numerous, and being only about half 
the size. 
6. N. iuflatus, pi. I. f. 4. — First Edition, pi. 52, f. 4; Montagu, sup. p. 81, 
pi. 18, f, 3. 
Shell spiral, with three lobed volutions ; the finst provided with five 
extremely ventricose articulations ; anterior end subglobose ; sij)hon situated 
as in N. Becarii. It is smaller, and less depressed than that shell, having 
only about half the number of articulations, which are much more tumid ; 
colour opaque brown. Found among sand on the Devonshire coast : rare. 
7. N. Imigatulus, pi. I, f. 9, 10. — First Edition, pi. 62, f. 9, 10 ; Montagu 
p. 188, pi. 18, f. 7, 8 ; Walker, f. 67. 
Shell spiral, with ten smooth, pale ferruginous brown, flexous ra}’’S marking 
the septa, which are rather deeper in colour, a little raised and radiating 
from the centre ; both sides are equally and considerably convex, declining 
towards the edge, which is rounded but not strictly caiinated ; aperture 
surrounded by a rim forming a triangle, so that the boily is not intersected 
by the anterior end, but the volution is lost just below the margin of the first 
septum; thus differing from the N. calcar, whose body is much clasped by 
the margin ot the anterior septum. Found at Sandwich and Seasaltar, rare. 
8. N. calcar, pi. I, f. 1, 2. — First Edition, pi. 52, f. 1, 2; Montagu, p. 189, 
pi. 16, f. 4 ; N. rotuius, Linnman Transactions, Vlil. p. ill. 
Shell smooth, spiral, body volution with six articulations, defined by flexous 
elevated striae, radiating from the cenfa’e, but do not quite reach the margin, 
which is provided wili a strong carina ; both sides of the shell equally 
convex, smooth, and more elevated in the centre ; interior volutions invisible 
after entering the aperture, which is semi-cordate in shape, claspiner the body 
equally on both sides, and provided with a small perforation ; colour brown. 
Found on the Devonshire coast, but very rare. 
9. N. crispus, pi. I, f. 6. — First Edition, pi. 62, f. 6 ; Montagu, p. 187, pi. 
18, f. 5 ; Walker, f. 65. 
Shell with lateral volutions, having about twenty flexous, crenulated arti- 
culations in the exterior volution, defined by elevated striae ; back carinated ; 
interior volutions hidden ; aperture semicordate, equal, lateral, clasping the 
body, and provided with a small siphon ; glossy and pure white. Found at 
Sandwich, Sheppy Island, Teignmouth, and Salcomb, Devonshire ; and at 
Weymouth and Swanago, Dorsetshire; also the south coast of Wales. 
10. N. carinatulus, pi. I, f. 7. — First Edition, pi. 52, f. 1 ; Montagu, p. 195 ; 
Walker, f. 72. 
“ An oblong carinated shell, with a narrow oval aperture ; colour whiteish, 
transparent like glass. From Seasalter and Sandwich; very rare.” We 
have copied this, imperfectlj’- figured and described. Shell from Walker. 
From the figure we should say that it belonged to the family Splierulacea of 
Lamarck. 
Family II. — Lituolacea. 
Shell somewhat spiral, the last volution continuous in a straight 
line. 
Genus 2. — Spirolina. — Lamarck . 
Shell multilocular, partly spiral, and discoid ; volutions con- 
tiguous, the la,st terminating in a straight line ; septa straight, 
perforated by a tube. 
Subdivision I. — Convoluted. 
1. S. suharcuatula, pi. I, f. 27. — First Edition, pi. 52, f. 27 ; Nautilus suhar- 
eualulus ; Montagu, sup. p. 80, pi. 19, f. I ; WaUier, f. 73. 
Shell subarcuated, subconvoluted, the straight p.art containing about five 
colls ; the po.sterior half convoluted ; twelve visible concamerations, and very 
distinct ; septii somewhat elevated ; back carinated, and slightly indented at 
the division of the cells ; anterior septa oblique, producing at the aperture a 
considerable slope from the back interiorly ; front margin not carinated, but 
obtusely rounded ; siphon, placed neai- the back. 
2. S. similitua, pi. I, f. 22.— First Edition, pi. 52, f. 22 ; Natitilus similituus ; 
Montagu, jj. 196, pi. 19, f. 3. 
Shell elongated, subarcuated, with elevated articulations; the septa pro- 
vided with small elevated tubercles, a row of larger ones in the centre of 
the back ; apex incurvated ; aperture with a small produced siphon ; colour 
opaque brown. Found at Sandwich and Sheppy Islands ; rare. 
Subdivision II. — Shells nearly straight, 
3. S. Legimen, pi. 1, f. 22, 23. — Orthoccra Legumen. — First Edition, pi. 52, 
f. 22, 23 ; Nautilus Legumen ; Montagu, sup. p. 82, pi. 19, f. 6, and A. Walker, 
f. 74. 
Shell subarcuated, smooth, glossy, pellucid, white ; slightly compressed, 
and a littfe tapeiing; the extremities rounded and somewhat contracted; ante- 
rior end surrounded by an oblique ridge, above which is an excerted siphon ; 
with a eon'iiderable aperture near to the concave side ; septa eight or nine in 
number, oblique, and visible through the shell ; cells gradually decreasing in 
size towards the posterior end. Fig. 23 represents the aperture with the siphon. 
Length about an eighth of an inch t breadth about a sixth its length. Found 
in sand on the coasts of Kent and South Devon ; very rare. 
Family III. — Orthocerata. 
Shell straight or nearly so, without any spiral volutions. 
Genus 3. — Nodosaria. — Lamarck . 
Shell elongated, erect, or smooth, and sliglitly arcuated, sub- 
conic, nodose, consisting of a series of spherical volutions ; the 
transverse septa perforated. 
1. N. subareuata, pi. I, f. 18. — Orthoccra subarcuata. — First Edition; Nau- 
tilus subarcuaius ; Montagu, 198, pi. 6, f. 5. 
Shell siibcylindrical, subarcuated, with throe distinct globose articulations at 
the superior end; the remiiiiiiiig divisions- impcrioetly defined, and abruptly 
