History of British animals - University of Guam Marine Laboratory

t. ccx. f. 1.— London Clay.3Modiola. MOLLUSCA. MYTILIDiE. 413420. M. Gibbsii.— Shell somewhat triangular, striated transversely,clothed with foliations, which are serrated on one edge.{Leach. Zool. Misc. ii. 34. t. lxxii. f. 2.) Turt. Biv. Brit. 200.—Westcoast of England." Shell about two inches long, and one and a half broad ; veryjflat and angularat the anterior side, regularly striated transversely, white and opake underthe skin, covered, more or less, with long foliations, which are constantlynotched down one of the sides."'-421. M.discrepans.— Shellinterruptedly longitudinallystriated, beaks obsolete, cuticle black. /Mytilus discrepans, Mont. Test. Brit. 167. and Sup. 65. t. xxvi. f. 4Modiola discrepans, Turt. Biv. Brit. 202. Linn. Trans Gregariousin deep water. At Newhaven it is called Corduroy Mussel.Sometimes reaching to two inches in length ; compressed and rounded atboth extremities ; surface of the shell divided into three compartments by alongitudinally striated space from the beaks along the back to the posteriorextremity, a smooth space from the beaks to the middle of the ventral margin,and another striated space, occupying a short space at the anterior extremity.There are distinct transverse wrinkles.422. M. discors.— Shell interruptedly longitudinally striated,beaks tumid, cuticle green.Mytilus discors, Linn. Syst.i. 1159. Mont. Test. Brit. 167.—Modioladiscors, Turt. Biv. Brit. 201. t. xv. f. 4, 5. — Adhering to Ascidiae andthe roots of Fuci.Shell seldom exceeding half an inch in length;resembling the last in itsmarkings, but in form more tumid, broader, and the anterior side shorter.EXTINCT SPECIES.1. M. depressa.— Much depressed, ovate, narrowing towards the posteriorside ;surface smooth.— Sower. Min. Conch, t. viii. the three upper figures.—London Clay.—The large middle figure is probably a distinct species belongingto the Lias.2. M. pallida.— Oblong, gibbous, smooth ; inferior margin straight, posteriorside slightly swelled, beaks obtuse.— Sower. Min. Conch, t. viii. threeright hand lower figures.— In Green Sand,3. M. Icevis.— Sub triangular, very smooth, convex; inferior and posteriormargins nearly straight, united by— a short curve, beaks small. Sower. Min.Conch, t. viii. left hand lower figure.— Lias.4. M. parallela.— Shell transverse, anterior and posterior sides parallel, coveredwith transverse furrows.— Sower. Min. Conch, t. ix. upper right handfigure.— Lias.5. M. elegans.— Oblong, gibbous, inferior margin straight, dentated ; anteriorside covered with transverse furrows ; posterior side swelling, smooth,with a few transverse furrows near the base.— Sower. Min. Conch, t. ix. lefthand upper, middle, and lower, figures —London Clay.G. M. subcarinata.— Oblong, smooth, gibbose ; anterior side keel-formed,rather obtuse; posterior lobe convex; front concave— Sower. Min. Conch.