56 



MOLLUSCA. 



[Gasteropoda 



4. LlMAX AGRESTIS, pi. XVIII,* f. 20. 



Limax agrestis, Limit', Syst. Nat., p. 1082, No. 6 ; Gmolin, 

 Linn. Syst. Nat., p. 3101, No. 63 Miiller, 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. Mom, p. 6; Limacella obliqua, 

 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, which 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.filans, var. 7 of Ferussac, as belong- 

 ing to this species. 



5. LlMAX GAGATES? VAR., pi. XVIII,* f. 21. 



Limax gagales ? 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 Hill, 

 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 Limacida?. 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 Hydrobranchije. 



The branchiae filamentary, or laminated, and pectinated, or 

 tufted. The animals respire in water. 



Family II Bullacea. 



The branchiae situate in a particular cavity, near the posterior 

 region of the back, and covered by a mantle; animal destitute 

 of tcntacula. 



All the animals of this family are destitute of a branchial 

 operculum, and the head very indistinctly formed. Some of 

 thriii 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 . — Bulla. — Linnceus. 

 Shell placed on the posterior portion 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; lb., 

 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., II, p. 364, pi. 13, f . 5 ; 



Fleming, p. 294. 



Shell cream-white, oblong-oval ; no visible spire ; apex urn- 

 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 striae ; 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 stria; 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 zonata, 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. 



