56 MOLLUSCA. • [Gasteropoda 
4. Limax agrestis, pi. XVIII,* f. 20. 
Limax agrestis, Linne, Syst. Nat., p. 1082, No. 6; Gmelin, 
Linn. Syst. Nat., p. 3101, No. 6 ; Muller, Verm., II, p. 8, No. 
204; Drapernaud, Hist, des Moll., p. 126, pi. 9, f. 9; Sturm, 
Fau. Abthl., VI, p. 1, pi. 4; Pennant, Brit. Zool., IV, p. 41 ; 
Lamarck, An. San. Vert., VI, pt. 2nd, p. 50; Fleming, Brit. 
An., p. 256; Turton, Brit. Fau., p. 133; Pfeiffer, I, p. 21; 
Nunneley, Trans. Phil. Soc. Leeds, pi. 1, f. 4; Alder, Mag. 
Zool. and Bot., II, p. 105; Thompson, Ann. and Mag. Nat. 
Hist., VI, p. 61; Forbes, Mai. Mon., p. 6; Lirmcella ohliqua, 
Brard, p. 148, pi. 4, f. 7, 8, 17, 18, shell; Limacellus obliquus, 
Turton, Man., p. 26, pi. 3, f. 17. 
Shell variable in form, very small, thick, hard, and of an 
oblong square, rounded at the corners ; colour, pale yellowish- 
white, or gray ; a little concave, and provided with a membra- 
neous edge. 
This species is destitute of the abrupt thickening in the 
centre of the shell, w'hich is so strongly characteristic of L. 
carinatus. 
Common in fields throughout Britain ; Mr. Clarke found it 
in Queen’s County, and County of Galway, Ireland. 
Mr. Clarke considers L.Jilans, var. 7 of Ferussac, as belong- 
ing to this species. 
5. Limax gagates? var., pi. XVHI,* f. 21. 
Limax gagates? var., Ferussac? Drapernaud? Limax No. 
4, Clarke, Ann. and Mag. Nat. Hist., VI, p. 19. 
Shell oval, somewhat spoon-shaped, pointed above, and 
rounded below ; membranaceous, and subopaque. 
Mr. Clarke says this shell differs materially in size and thick- 
ness from L. variegatus, being smaller, more membranaceous, 
and less opaque. The colour and markings of the animal are 
also very different from other British species. 
Discovered by the Rev. B. J. Clarke, of Tuam, at Spire Flill, 
La Bergerie, Queen’s County, Ireland, who has most obligingly 
sent me the use of beautiful drawings of the animal and shell 
of this as well as of all the other Irish Limacidae. He says it 
is always found on trees, and never in cellars and damp vaults, 
&c., as L. variegatus. 
Mr. Thompson, in his paper on the Land and Fresh Water 
Mollusca of Ireland, remarks, “ It may be the L. carinatus of 
Leach, or L. gagates of Drapernaud;” but I do not think Mr. 
Clarke’s description agrees with either of the above species. I 
think it more than probable that it is an entirely new species. 
Division II. — Hydrobranchi^. 
The branchiae filamentary, or laminated, and pectinated, or 
tufted. The animals respire in water. 
Family H — Bullacea. 
The branchiae situate in a particular cavity, near the posterior 
region of the back, and covered by a mantle ; animal destitute 
of tentacula. 
All the animals of this family are destitute of a branchial 
operculum, and the head very indistinctly formed. Some of 
. them are devoid of both external and internal shell. In some 
species it is concealed in the mantle, and in several there is an 
external shell attached by a muscle. 
The shells are so widened, that there is no apparent colu- 
mella. 
Genus 5. — Bulla. — Linnaeus. 
Shell convolute, oblong, oval, or cylindrical, with a depression 
above in place of a spire, the inner volutions being concave in 
the exterior one ; aperture longitudinal, as long, or longer than 
the convolutions, straitened above and expanded below, in which 
situation it is diffuse ; outer lip thin ; columellar lip generally 
reflected, with a coating of shelly matter. 
Sub-Genus 1. — Bvlla. — Linnceus. 
Shell placed on the posterior qiortion of the body of the ani- 
mal, and provided with an epidermis. 
1. Bulla lignaria, pi. XIX, f. 23, 24. — First Ed., pi. 38, 
f. 23, 24. 
Bulla lignaria, Linne, Syst. Nat., p. 1184; Lamarck, An. 
San. Vert., VI, pt. 2nd, p. 53 ; Pennant, Brit. Zool., IV, p. 
126, pi. 70, f. 83 ; Montagu, Test. Brit., p. 205 ; Donovan, pi. 
27; Fleming, Brit. An., p.92; Maton and Rackett, p. 125; Ib., 
Ency. Meth., pi. 359, f. 3 ; Forbes, p. 6. 
Shell oblong-oval, thin; spire concealed, subumbilicated, 
being enveloped in the body volution ; aperture glossy, bluish- 
white internally, extending the whole length of the shell, narrow 
above, and abruptly expanding below, terminating in a rounded 
base ; outer lip thin at the edge ; inner lip pretty broadly re- 
flected over the columella; surface transversely striate, of a pale 
reddish-yellow, with numerous, transverse, burnt terra-sienna 
coloured double lines, producing a wood-like appearance ; lon- 
gitudinal lines of growth distinct, frequently interrupting the 
transverse ones. 
This beautiful shell is by no means uncommon in all the seas 
around Great Britain and Ireland. On the coasts of the latter 
country it grows to a large size. 
2. Bulla alba, pi. VIII, f. 3 — First Ed., pi. 51, f. 3. 
Bulla alba, Turton, Zool. Journ., H, p. 364, pi. 13, f. 5 ; 
Fleming, p. 294. 
Shell cream-white, oblong-oval; no visible spire; apex um- 
bilicate ; aperture extending the whole length of the body, 
narrow above, its lower half very wide, terminating in a well 
rounded base ; outer lip sharp at the edge, and not elevated 
above the body; inner lip rather broadly reflected on the colu- 
mella ; whole external surface with slight longitudinal strias ; at 
each extremity, three transverse punctured striae. 
Dr. Turton remarks, “they are more elongated than the 
Bulla ampulla, and essentially differ in having only three 
rather remote, transverse striae at each end, whereas in the 
latter there are seven or eight striae on the lower extremity, 
and none on the upper.” 
Dredged in the British Channel by Dr. Turton, who says he 
got six dead specimens in one locality. 
3. Bulla zonata. 
Bulla sonata, Turton, Mag. Nat. Hist., VII, p. 352 ; Bulla 
scaphander, Leach. 
“ Shell oval, solid, opaque, with alternate zones of white and 
fulvous, and transverse lines of minute raised dots. Length a 
quarter of an inch ; breadth nearly as much. 
