34 MOLLUSCA. [Trachelipoda 
at the junction of the volutions; outer volution exhibiting three 
white curved, remote, equidistant lines, radiating from the um- 
bilicus; these are the internal septa which divide the chambers; 
under side nearly flat, and umbilicated; aperture oval, and 
somewhat triangular; outer lip interrupted. Diameter not a 
quarter of an inch. 
Found in stagnant water, adhering to aquatic plants. 
This shell may be easily confounded with the Planorbis 
nitidus, but if inspected through a lens the concamerations will 
be at once perceived. 
Family IX. — Colimacea. 
Spiral ; destitute of any exterior projections, except the 
additions of growth ; outer lip frequently reflected ; terrestrial 
or amphibious ; tentacles of the animal cylindrical, with or 
without an operculum. 
Section I. — Animals with two tentacles. 
Genus 42. — Cyclostoma. — Lamarck. 
Shell turbinated, variable in shape, thin ; the apex in most 
species obtuse, and the volutions ventricose ; aperture entire, 
circular, or nearly so in the adult state ; outer lip more or less 
angular at the upper part, sometimes thickened, usually reflected 
and united all round, and frequently externally fringed ; oper- 
culum spiral, horny, but inclining to testaceous in some species, 
consisting of a few depressed convolutions, provided with a sim- 
ple testaceous internal coating. 
1. Cyclostoma elegans, pi. XIV, f. 28 — First Ed., pi. 
41, f. 28. 
Cyclostoma elegans^ Drapernaud, p. 32, pi. 1, f. 5 and 8; 
Lamarck, An. San. Vert., VI, pt. 2nd, p. 148 ; Pfeiffer, p. 74, 
pi. 4, f. 30, 31 ; Turton, Man., p. 93, f. 75; Fleming, Brit. An., 
p. 257; Alder, Mag. Zool. and Bot., II, p. 112; Brard, p. 103, 
pi. 3, f. 7, 8; Jeffreys, Linn. Tr., XVI, p. 63; Thompson, Ann. 
and Mag. Nat. Hist., VI, p. 51 ; Cyclostomus elegans, De 
Montfort, II, p. 287 ; Turbo elegans, Montagu, Test. Brit., p. 
342, pi. 22, f. 7; Maton and Rackett, Linn. Tr., VIII, p. 167; 
Brown, Wernerian Mem., II, p. 522 ; Ib., Ency. Brit., VI, p. 
456; Fleming, Edin. Ency., VII, p. 74, pi. 203, f. 10; Turbo 
tumidus. Pennant, Brit. Zool., IV, p. 128, pi. 82, f. 110; Turbo 
striatus, Da Costa, p. 86, pi. 5, f. 9; Donovan, Brit. Sh., II, pi. 
59 ; Nerita elegans, Muller, Verm., II, p. 177* 
Shell tapering, oblong-ovate ; body large, tumid ; spire con- 
sisting of four ventricose volutions, and ending in an obtuse 
apex; whole external surface provided with numerous, close-set, 
raised, spiral striae, crossed by finer longitudinal striae, producing 
a reticulated appearance ; aperture round, with a slight angular 
contraction above; outer lip thin, smooth on the edge, and con- 
tinuous ; inner lip slightly reflected on the columella, with a 
subumbilicus behind ; colour usually cinereous, with a purplish 
tinge, and reddish-purple at the apex; frequently fasciated with 
two rows of purplish-brown spots, or interrupted bands, or in 
some instances longitudinally streaked with a similar colour ; 
operculum horny externally, and testaceous on its inner surface, 
with a single depressed spiral line, and a series of fine striae 
radiating from it towards the circumference. Length five- 
eighths of an inch ; breadth three-eighths. 
Found in the Limestone districts of England and Wales; 
and Portrush, Ireland. 
2. Cyclostoma marmorea, pi. XVIII, f. 15. 
Cyclostoma marmorea. Brown, Edin. Jour. Nat. and Geo. 
Science, I, p. 12, pi. 1, f. 10, 11. 
Shell oblong-ovate; body large, inflated; spire small, con- 
sisting of four deeply divided volutions, abruptly tapering to 
an obtuse apex ; aperture quite orbicular ; outer lip united all 
round; pillar lip slightly reflected on the columella, behind 
which is a deep umbilicus ; whole surface smooth, glossy, of a 
pale ash colour, covered with zig-zag markings of a reddish 
chestnut-brown, which form four spiral fasciae on the lower 
volution, and gradually become obsolete on the superior por- 
tion of the spire. 
I noticed this elegant shell in the cabinet of my friend James 
Gerard, Esq., Edinburgh, associated with some British speci- 
mens of Cyclostoma elegans, to which it is closely allied in 
form, but may at once be distinguished from that shell in being 
totally devoid of striae, which in the elegans are very strong and 
conspicuous. 
Genus 43. — Carychium. — Muller. 
Shell oblong or cylindrical, with gradually increasing volu- 
tions, few in number; aperture straight, short, with folds on 
the columella. 
1. Carychium minimum, pi. XIV, f. 10, and pi. XVIII, f. 
15. — First Ed., pi. 41, f. 10. 
Carychium minimum, Muller, Verm., II, p. 125; Pfeiffer, I, 
p. 72, pi. 3, f. 45, 46; Leach, Moll., p. 133; Jeffreys, Linn. 
Tr., XVI, p. 365 ; Fleming, Brit. An., p. 270 ; Forbes, Mai. 
Mon., p. 12 ; Alder, Mag. Zool. and Bot., II, p. 114; Thomp- 
son, Ann. and Mag. Nat. Hist., VI, p. 42 ; Odostomo carychium, 
Fleming, Edin. Ency., VH, p. 76; Auricella carychium, Hart- 
man, p. 49 ; Auricula minima, Drapernaud, Moll., p. 57, pi. 3, 
f. 18, 19; Turbo carychium, Montagu, Test. Brit., p. 339, pi. 
22, f. 2; Maton and Rackett, Linn. Tr., VHI, p. 184; Brown, 
Ency. Brit., 6th Ed, VI, p. 457- 
Shell conic, glossy, pellucid, white ; body and spire of about 
equal length; the latter consisting of four very gradually taper- 
ing, minutely striated volutions, well defined by the suture, 
terminating in a somewhat obtuse apex ; aperture semioval, or 
auriform,. rounded both above and below; columella provided 
with two tooth-like folds, and sometimes a small rudimentary 
one above the others ; outer lip with a thickened margin, and 
in its centre a tooth-like knob. Length hardly a line; breadth 
one-third its length. 
This is the most minute of all the land shells, and is found 
pretty generally diffused at the roots of grass, or on mossy 
banks, in woods, and other moist situations. 
Genus 44. — Acme. — Hartmann. 
Shell subcylindrical, terminating in a blunted apex ; aperture 
ovate, simple ; outer lip simple, thin, slightly reflected over the 
columella, forming a subumbilicus. 
1. Acme fusca, pi. XIV, f. 25.— First Ed., pi. 41, f. 25. 
Acme lineata, Hartmann, Sturm, Faun., pi. 1, f. 4; Acme 
fusca, Thompson, Ann. and Mag. Nat. Hist., VI, p. 43; Turbo 
