Illustrations of the recent conchology of Great Britain and Ireland, with the description and localities of all the species, marine, land and fresh water

34 MOLLUSCA. [TRACHELIPODA at the junction of the volutions; outcr volution cxhibiting thrcc white curved, remole, equidistant lines, radiating from the um- bilicus ; these are the interna! septa which divide thc chambers; un<ler side nearly ílat, and umbilicated; apcrturc oval, and somewhat triangular; outer lip intcrrupted. Diamcter not a quarter of :m inch. Found in stagnant water, adhering to aquatic plants. This shell may be casily confoun<lcd with the Plano,·bis nitidus, but if inspectcd through a lens the concamerations will be at once perceivecl. FAMILY IX~CoLJMACEA. Spiral ; destitute of any exterior projections, except the ad<litions of growth ; outer lip frequcntly reflcctcd; terrestrial or amphibious; tcntaclcs of thc animal cylin<lrical, with or without an operculum. Scction l~Animals with two tentacles. GENUS 42,-CYCLOSTO~JA~Lamarck. Shell turbinated, variable in shapc, thin ; the apex in most species obtuse, an<l the volutions ventricose; aperture entire, circular, or nearly so in the a<lult state; outer lip more or less angular at the upper part, sometimes thickene<l, usually reflccted ami united ali roun<l, and frec¡uently externally fringe<l; opcr- culum spiral, horny, but inclining to testaceous in some species, consisling of a fcw clepressecl convolutions, provicled with a sim- ple testaceous interna! coating. I. CYCLOSTOMA ELEGANS, pi. XIV, f. 28~First Ed., pi. ,IJ, f . 28. q¡clostomc, clegcms, Drapernaud, p. 32, pi. 1, f. 5 ancl 8; Lamarck, An. San. Vert., VI, pt. 2nd, p. 148; Pfciffer, p. 74, pi. ,1, f. 30, 31; Turton, Man., p. 93, f. 75; Fleming, Brit. An., p. 257; Alclcr, Mag. Zoo!. ami Bot ., II, p. 112; Brard, p. 103, pi. 3, f. 7, 8; Jelfreys, Linn. Tr., XVI, p. 63; Thompson, Ann. ami Mag. Nat. I·Iist., VI, p. 51; C!Jclostomus clcga11s, De l\fontfort, II, p. 287; T1trbo clegans, l\fontagu, Test. Brit., p. :M2, pl. 22, f. 7; Maton and Rackett, Linn. Tr., VIII, p. 167; Ilrown, '\,Vernerian Mem., II, p. 522; lb., Ency. Brit., VI, p. 456; Flcming, Eclin. Ency., VII, p. 74, pi. 203, f. 10; Tm·bo lltmicl11s, Pennant, Brit. Zool., IV, p. 128, pi. 82, f. 110; Tu,·bo striat11s, Da Costa, p. 86, pi. 5, f. 9; Donovan, Brit. Sh., II, pi. 59 ; 1Ye1·it1, elcgm1s, l\Iiiller, Verm., II, p. 177. Shell tapering, oblong-o\·ate; bocly large, tumid; spire con- ~isling of four Yentricose volntions, ami ending in an obtuse apex; whole externa\ snrface prol'ide<l with numerous, close-set, raisecl, spiral str.i.c, crossecl by finer longitudinal stri.c, producing a reticulated appcarance; apertnre rouncl, with a slight angular contraction aboYo; onter lip !hin, smooth on the cclge, and con- tinuous; inner lip slightly rcflectecl on the columella, with a subumbilicus bchincl; colour usually cinereous, with a purplish tinge, ami reddish-purple at the apex; frequently fasciated with two rows of purplish-brown spots, or interrupted ban<ls, or in some instances longitmlinally streaked with a similar colour ; opcrculmn horny externally, ami tcstaceous on its inner surface, with a single cleprcssed spira\ line, ami a series of fine stri;c radiating from it towarcls the circumfcrcnce. Len,,th lh-e- l'ighths of an inch; breadth three-ei"hths. 0 o Found in the Limestone <listricts of England ancl Wales; and Portrush, Ireland. 2. CYCLOSTOM,I. MARM0REA, pl. XVIII, f. 15. Cgclostoma marmo,·ea, Brown, Edin. Jour. Nat. and Geo. Science, I, p. 12, pi. 1, f. 10, 1 l. Shell oblong-ovate; bo<ly largc, inllate<l; spire small, con- sisting of four decply divided volutions, abruptly tapering to an obtuse apex; aperturc quite orbicular; outer lip united ali roun<l; pillar lip slightly reflected on the columella, behincl which is a deep umbilieus; whole surface smooth, glossy, of a pale ash colour, eovered with zig-zag markings of a rc<l<lish chestnut-brown, which forro four spiral fascim on the lower volution, and gra<lually become obsolete on the superior por- tion of the spire. I noticed this elegant shell in the cabinet of my fricn<l James Gerard, Esq., Edinburgh, associated with sorne British speci- mens of Cgclostoma elegans, to which it is closcly allie<l in form, but may al once be distinguished from that shell in being totally devoid of stri.c, which in the clcgans are very strong ami conspicuous. GENUS 43.-CAnYCHIUM.-Miillcr. Shell oblong or cylin<lrical, with gradually increasing volu- tions, fcw in number; apcrture straight, short, with folcls on the columella. 1. C,1.nvcmuM MJNIMU~J, pi. XIV, f. 10, and pi. XVIII, f. 15.-First Ed., pi. ,11, f. 10. Cm'!}chittm mínimum, Miillcr, Verm., II, p. 125; Pfciffer, I, p. 72, pi. 3, f. 45, 46; Leach, Moll., p. 133; Jeffreys, Linn. Tr., XVI, p. 365 ; Fleming, Brit. A11., p. 270; Forbes, Mal. Mon., p. 12; Alder, Mag. Zoo!. ami Bot., II, p. 114; Thomp- son, Ann. ancl Mag. Nat. Hist., VI, p. 42; Odostomo ca,'!Jchium, Fleming, E<lin. Ency., VII, p. 76; Am·icella C<t?'!}chittm, Hart- man, p. 49; Am·icula minima, Drapernaucl, Moll., p. 57, pi. 3, f. 18, 19; Turbo ca,'!Jcl1ium, Montngu, Test. Brit., p. 339, pi. 22, f. 2; Maton and Rackett, Linn. Tr., VIII, p. 184; Brown, Ency. Brit., 6th Ecl., VI, p. 457. Shell conic, glossy, pcllucid, white; body and spire of about equal length; the !alter consisting of fou r very graclually taper- ing, rninutely striated volutions, well define<l by the suture, terminating in a somewhat obtuse apex; aperture semioval, or auriform, rouncle<l both above and below; columella providcd with two tooth-likc fol<ls, and somctimes a small rudimentarv one above the others; outcr lip with a thickened margin, an;I in its centre a tooth-like knob. Length hardly a line; br('adth one-third its length. This is the most minute of ali the land shells, and is founcl pretty generally diffused at the roots of grass, 01· on mossy banks, in woo<ls, and other moist situations. GENus 44-Ac~m-I·Iartmann. Shell subcylin<lrical, terminating in a blunted apex; aperture ovale, simple; outer lip simple, thin, slightly rcllected 01·er the columella, forming a subumbilicus. 1. Ac~tE FUSCA, pi. XIV, f. ~5.-First Ecl., pi. 41, f. 2:i. Acmc lilleata, Hartmaun, Sturm, Faun., pl. 1, f•. ¡; .Ac11w fusca, Thompson, Ann. ami .i'lfag. Nat. 1-list., VI, p. •13; Turbo