History of British animals - University of Guam Marine Laboratory

320 MOLLUSCA. PECTINIBRANCHIA. Natica.nous lines ; pillar-cavity very large. This species has occurred only to MrDonovan.276. N. tubcrosissima.— Whorls four, marked with four spiralbroken tubercular ridges.Nerita tub. Mont. Test. Brit. Sup. 150. t. xxix. 5.— At f. Dunbar, MrLaskey.Breadth about |th of an inch; pellucid, white; upper volutions small ;pillar-cavity large.277. N. sulcata.— Whorls four, with remote oblique transversestriae.Nerita sul, Turton. Conch. Diet. 124. fig. 56, 57 N. glabrissimus,Brown, Wern. Mem. ii. 532. t. xxiv. f, 12—Two specimens found inDublin Bay by Dr Turton.Breadth |th of an inch ; globular, semitransparent, bluish-white ; whorlsswollen, well defined ; pillar-lip flat, projecting a little in the middle overthe cavity behind, which is long and deep.278. N. pallidula.— Whorls three, pillar-lipwith a widegroove leading to the cavity.Ner. pall. Don. Brit. Sh. t. xvi. f. i. Mont. Test. Brit. 468 Turbo pallidusand puteolus, Turt. Conch. 192.—Among seawater-mark, common.weeds, about lowLength \ an inch, breadth |ths ; yellowish-brown whorls rounded, with;a grooved separating line, the upper ones small, lateral, and little produced,slightly wrinkled by the layers of growth ; pillar-cavity deep, the retral extremityof the lip partly folded over it ; operculum with diverging wrinkles.-279- N. lacuna. — Whorls four ;pillar-lipwith a narrowgroove leading to the cavity.Ner. lac. Mont. Test. Brit. 428. t. xiii. f. 6—Turbo lacuna, Turt. Conch.Diet. 193. t. xxv. f. 87, 89.—On the English shores, rare.This shell bears a very close resemblance to the preceding. Judging froman authentic example which I received from Mr Montagu, it chiefly differsin the less enlargement of the body-whorl towards the aperture, the secondwhorl being better defined, the pillar-groove narrower, and the anteal curvatureof the lip more restricted : there are likewise some faint traces of spiralstriae.EXTINCT SPECIES.1. N. glaucinoides.—Nearly globose spire, rather elongated ; pillar-cavitysimple, partly covered ; upper part of each whorl slightly depressed— Sower.Min. Conch, t. v. three upper figures, and t. cccclxxix. f. — 4. London Clay andSuffolk Crag.2. N. similis.— Shell rather rhomboidal ; spire short ;pillar cavity— dividedby a spiral projection ; aperture slightly angular above. Sower. Min. Conch.t. v. two middle figures —London Clay.3. N. depressa Nearly globose, subumbilicated ; upper part, and the sideof each whorl, flattened, so as to appear nearly square columella ; depressedbeneath ; aperture angular at the upper part.—Sower. Min. Conch, t. v. lowerfigures.— Crag-marl.