Involute.] MOLLUSCA. 



Genus 3 Arion. — Ferussac. 



Shell an oblong mass of granular, spongy, corneous substance, 

 enveloped in the mantle of the animal, sometimes consisting 

 only of a few granules in a rudimentary condition. 



Section I Shell oval and concave. 



1. Arion hortensis. 



Variety 1. Animal black, with gray streaks. 

 Arion hortensis, Ferussac, Moll., 6, pi. 11, f. 4, 5, 6, VIII, 



a, f. 2, 3, 4; Gray, Med. Rep., 1821 ; Thompson, Ann. and 

 Mao-. Nat. Hist., VII, p. 18; Limax subfuscatus, Pfeiffer, pi. 

 4, f. 20 ; Limax hortensis, Grateloup, Moll. Dax., p. 55, f. 4 ; 

 Limacellus variegatus, Turton, Man., p. 25, pi. 3, f. 16, shell; 

 Limacella concava, Braid, p. 121, shell. 



Varieti/ 2. Animal gray, with a black streak on both sides. 



Arion hortensis, var. /3, Alder, Mag. Zool. and Bot., II, p. 

 105; Arion circumscriptum, Johnston, Edin. New Phil. Journ., 

 V, p. 77 ; Limax fasciatus, Nilsson, Fau. Succ, p. 3. 



Shell oval, misshapen, and somewhat concave. 



Inhabits woods in Great Britain and Ireland ; in the latter 

 country, Thompson says it is common throughout the North. 



Section II. — Shell, if any, nearly circular, spongy, and 

 rudimentary. 



2. Arion empiricorum. 

 Arion empiricorum, Ferussac, Hist. Moll., 60, p. 17, pi. 1, f. 



23; Alder, Mag. Zool. and Bot., II, p. 105; Arion ater, 

 Thompson, Ann. and Mag. Nat. Hist., VII, p. 18; Limax ater, 

 Linne, Fau. Succ, p. 507 ; Miiller, Verm., II, p. 2 ; Draper- 

 naud, p. 122, pi. 9, f. 3, 4, 5, 6 ; Nunneley, Trans. Phil. Soc. 

 Leeds, p. 46, pi. 1, f. 1, pi. 2, f. 1, pi. 1, f. 1, 3, and 6; Limax 

 Rufus, Drapernaud, p. 123, pi. 9> f. 6. 



Shell spongy, sub-hemispherical. 



This species' is very common throughout Great Britain and 

 Ireland, in gardens and woods. Miss M. Ball says the yellow 

 variety is found in the North and South. 



Genus 4. — Limax Linnaeus. 



Shell oblong, suhquadrate, scutiform, extremely thin, and 

 crystalline; covered with a pale brown epidermis, which extends 

 beyond the margin of the shell ; apex rounded, not convolute, 

 but provided with a cavity at the top. 



Section I. — Mantle of the. animal produced behind; shell 



55 



1. Limax maximus, pi. XVIII,* f. 17. 



Limax maximus, Linnaeus, Syst. Nat., p. 1081, No. 4; 

 Thompson, Ann. and Mag. Nat. Hist., VI, p. 18; Limax 

 cinereus, Miiller, Verm., II, p. 8, No. 204; Gmelin, Syst. Nat., 

 I, p. 3101 ; Alder, Mag. Zool. and Bot., II, p. 105; Forbes, 

 Mai. Mon., p. 6; Limax antiquorum, Ferussac, Hist., p. 68, pi. 

 4, f. 8, a, f. 1, pi. 4, f. 4, shell; Limax maculatus, Leach, MSS. ; 

 Nunneley, Trans. Phil. Soc. Leeds, I, p. 46, pi. 1, f. 2; Lima- 

 cella Parma, Brard, p. 110, pi. 4, f. 1, 2, 9, 10, shell; Lima- 

 celltis Parma, Turton, Man., p. 24, pi. 2, f. 14, shell. 



Shell thin, cream-white, subdiaphanous, depressed, slightly 

 concave internally ; aperture nearly the whole size of the shell, 

 with the margin of the outer lip membranaceous, and very thin; 

 external surface slightly wrinkled transversely, and sometimes 



studded with minute, glistening, crystalline particles; apophysis 

 of adhesion, small, prominent, situate on the extremity of the 

 top, or broader end ; opposite end rounded, and very thin. 

 Length about six lines; breadtli four lines. 



This species is common all over Great Britain and Ireland, 

 and the Isle of Man, frequenting the bottoms of hedges and 

 damp situations. 



The Rev. B. J. Clarke, of Tuam, has kindly sent me a draw- 

 ing of a very distinct variety of this animal. 



Section II. — Shell depressed ; mantle of the animal short, 

 and posteriorly rounded. 



2. Limax flavus, pi. XVIII,* f. 18. 

 Limax favus, Linnaeus, Syst. Nat., p. 1082; lb., Fau. Suec, 



p. 363, No. 2092; Pennant, Brit. Zool., IV, p. 41 ; Latham, 

 Linn. Trans., I, p. 182; Thompson, Ann. and Mag. Nat. Hist., 

 VI, p. 18; Limax variegatus, Drapernaud, p. 127; Ferussac, 

 Prod., p. 21 ; lb., Hist. Moll., p. 71, pi. 5, f. 1 to 6 ; Alder, 

 Mag. Zool. and Bot., II, p. 105 ; Nunneley, Trans. Phil. Soc. 

 Leeds, I, p. 47, pi- 1, f. 3; Limax succino colore, Lister, 

 Conch., pi. 101, f. 6; Limacella concava, Brard, p. 121, pi. 4, 

 f. 5, 6, 13, 14, shell; Limacellus variegatus, Turton, Man., p. 

 25, pi. 3, f. 16. 



Shell extremely thin, shield-shaped, slightly concave; anterior 

 edge a little rounded; posterior end mammilliform ; of a pale, 

 yellowish colour. 



Frequents cellars, in London and its vicinity, and has been 

 met with at Oxford, Plymouth, Bristol, and Bath; and was dis- 

 covered at Youghal, Ireland, by Robert Ball, Esq., and has also 

 been found in the North by William Thompson, Esq., of 

 Belfast. 



Section III. — Mantle short, truncated behind ; shell thick, 

 convex beneath, and oval. 



3. Limax carinatus, pi. XVIII,* f. 19. 

 Limax carinatus, Leach, Moll., p. 73, pi. 8, f. 1 ; Alder, 



Mag. Zool. and Bot., II, p. 105 ; Thompson, Ann. and Mag. 

 Nat. Hist., VI, p. 63 ; Limax Sowerbii, Ferussac, Hist. Moll., 

 pi. 8, f. 7, 8; Denson, Mag. Nat. Hist., VI, p. 694, f. 120, a, b; 

 Limacella ungxdata, Brard, p. 1 16, pi. 4, f. 3, 4, 1 1, 12; Lima- 

 cellus ungulatus, Turton, Man., p. 25, pi. 3, f. 15. 



Shell oval, or rhombic, rather thick, and convex beneath, of 

 a pale cream-white ; margin rather broad, rufous towards the 

 top ; destitute of a membrane, and never concave. 



Mr. Clarke remarks, that "the peculiar thickening process in 

 the centre gives them the appearance of having a marginal 

 zone, or as if a smaller sized shell were placed on the top and 

 centre of the larger, leaving a rather broad margin, which is 

 usually of a rufous colour towards the top." 



Inhabits gardens, in the vicinity of London, and at Hamp- 

 stead; also at La Bergerie; Monivea, County of Galway, under 

 stones in fields, and in tufted plants in gardens, according to the 

 Rev. B. J. Clarke, by whom it was first noticed in Ireland. 



Mr. Thompson (p. 63) mentions a species obtained by him. 

 in 1840, near Clifden, Connemara, Ireland, while on a tour with 

 Professor Forbes, King's College, London, and Robt. Ball, Esq., 

 of the Castle, Dublin, which were more nearly allied to the L. 

 gagates of Drapernaud, than the British specimens of L. cari- 

 natus. Mr. Ball has since found it on the Circular road, Dublin. 



