24 



MOLL USC A. 



[TllALHELIPODA. 



rounded above, and slightly contracted below, inside of a fine 

 purple hue ; outer lip thin, slightly reflected ; inner lip broad, 

 flattened as in Haliotis, and white; outside covered with a 

 rather smooth fuscous epidermis. Length about a tenth of an 

 inch. 



Found by Dr. Leach on the Devonshire coast. 



3. G. Otis; Helix apertura patentessinue, Walker, Min. 

 Sh, pi. I, f. 17 ; Helix Otis, Turton, Conch. Die, p. 70; Ve- 

 lutina Otis, Fleming, Brit. An., p. 326. 



Shell transversely oblong; with three smooth, scmitransparent, 

 glossy volutions ; aperture transversely oblong ; outer lip thin ; 

 inner lip a little thickened and flatfish. 



Family V. — Ianthinia. 

 Animal capable of raising itself in the water, and floating. 



Genus 30 — Ianthina — Lamarck. 



Animal provided with a visicle, attached to its foot, by means 

 of which it can raise itself to the surface of the water, and float 

 on the ocean. 



Shell ventricose, subglobose, and subconic; thin, diaphanous, 

 and brittle; aperture subtriangular, produced at its lower region 

 and at its outer side, but is considerably rounded at the angle 

 formed by the union of the upper and lower halves of the outer 

 lip ; columella straight, and elongated beyond the base of the 

 outer lip, with the inner lip reflected over it ; the outer lip 

 formed into an angular sinus, by the projection of its upper 

 half. 



1. /. communis, pi. VIII, f. 1, 2 First Ed., pi. 51, f. 1,2; 



Ianthina communis, Lamarck, VI, pt. 2nd, p. 20G ; Fleming, 

 Brit. An., p. 326; Ianthina fragilis, Ency. Meth., pi. 456. f. 1, 

 a, b ; Helix ianthena, Gmelin, Linne, 3645, No. 103; Helix 

 ianthina, Brown, Wernerian Memoirs, II, p. 525 ; lb., Ency. 

 Brit., VI, p. 460, pi. 155, f. 6. 



Shell subconic, umbilicate; body extremely large; spire very 

 small, consisting of three somewhat inflated volutions, separated 

 by a deep suture, terminating in an obtuse apex, on the pinnacle 

 of which is inserted a very small bead-like process, of a pearla- 

 ceous lustre ; the centre of the body produced into a rounded, 

 subcarinated ridge ; base produced ; aperture subtriangular, 

 smooth, and glossy within, much produced below ; outer lip 

 greatly expanded, thin, and acute ; inner lip straight, somewhat 

 reflected over the small umbilicus; whole shell covered with 

 undulous, rather wide spiral striae, and crossed by strong irregu- 

 lar stria;, following the direction of the lines of growth ; colour 

 of a reddish purple, or lilac, the superior volutions whitish. 

 Length upwards of an inch ; breadth nearly an inch and a 

 (piarter. 



Many hundreds of this shell were found alive at Portiush, 

 county of Antrim, Ireland, by Mrs. Clewlow and Miss Kelly, of 

 Belfast, after a storm. Some of them floated on the surface of 

 the sea, and were buoyed up by the reticulated, viscous mem- 

 brane which is attached to the foot of the animal. It was after- 

 wards found alive in Bantry Bay, by Miss Hutohins, and has 

 since been met with on various parts of the coast of Ireland, 

 and Wales. 



2. /. exigua, pi. VIII, f. 16, 17; lanlhinn cxigua, Lamarck, 

 VI, pt. 2nd, p. 206 ; Ency. Method., pi. 156, f. 2, a, I,. 



Shell ovate-conical, very thin, subh\ aline, with four rounded 

 volutions ; spire produced, terminating in a subacute apex, and 

 elegantly striated longitudinally ; aperture triangular ; pillar lip 

 curved, and terminating in a produced, oblique point; the whole 

 shell of a beautiful reddish violet colour. Length two lines and 

 a half; breadth two lines. 



Found by my friend R. J. Shuttleworth, Esq., at Conomaura, 

 west coast of Ireland. 



Family VI. — Neritacea. 

 Shells subglobose, or oval; destitute of a columella; the outer 

 lip margined and transverse ; aperture enclosed by an opercu- 

 lum. They inhabit both the sea and fresh waters. 



Genus 31 Natica Adamson. 



Shell subglobose, oval, or oblong ; umbilicate ; spire short, 

 sometimes very short, with the apex very rarely pointed; aper- 

 ture large, semicircular, and very seldom effuse ; outer lip sharp 

 edged, smooth within; columellar lip oblique, destitute of teeth, 

 generally thickened, and sometimes spread thickly over the um- 

 bilicus; umbilicus usually large, having a spiral callosity within, 

 which sometimes increases so as to cover the umbilicus ; it is 

 sometimes very small, and in a few instances nearly obsolete, so 

 much so, as to be hardly perceptible ; operculum testaceous in 

 some species, and horny in others. 



1. iV. monilifera, pi. XIII, f. 1, 2, 8, and 10 First Ed., pi. 



43, f. 1, 2, 8, and 10; Natica monilifera, Lamarck, An. San. 

 Vert., VI, pt. 2nd, p. 196; Forbes, Mai. Mon., p. 29; N. glau- 

 cina, Fleming, Brit. An., p. 319; Nerita glaucina, Donovan, 

 Brit. Sh., I, pi. 20, f. 1 ; Brown, Ency. Brit., VI, p. 462; Maton 

 and Racket, Linn. Tr., VIII, p. ; Montagu, Test. Brit., p. 

 469; Turton, Brit. Fa., p. 195. 



Shell subglobose, strong, smooth, glossy; spire small, consist- 

 ing of six somewhat inflated, rapidly decreasing volutions, slightly 

 flattened above, and well defined by the suture; body very large 

 in proportion to the spire, and ventricose; aperture suboval and 

 sublunate ; outer lip thin and even, and considerably protruded 

 at its juncture with the body ; pillar lip thick, callous, broadly 

 spread over the columella above, narrowed beneath, and slightly 

 reflected over the umbilicus, which is large, deep, and striated 

 internally ; whole shell covered with minute, nearly obsolete, 

 irregular, longitudinal striae, which are only perceptible by the 

 aid of a lens ; colour sometimes livid, or purplish, but for the 

 most part ferruginous, or chestnut, with a series of longitudinal 

 purplish-brown streaks on the superior portion of the volutions; 

 operculum horny, very thin, transparent, and clastic, with diver- 

 gent stria?. The young shell, f. 1, 2, is generally ornamented 

 with a scries of streaks, or girdles of spots, or zig-zag lines. Size 

 varying from an inch and a half to two inches in length ; and 

 from an inch and a quarter to an inch and a half in diameter. 



Found on most of the British and Irish coasts, and seems to 

 be a deep water species. Mr. Nicol states that he found it 

 buried in sand, at very low tides, in the Frith of Forth. 



Mr. Forbes, in his " Malacologia Monensis," says, the body 

 of this species is "minutely striated spirally." I have examined 

 specimens from almost every coast in the kingdom, and have 

 never met with ;\ single specimen with this character. 



