History of British animals - University of Guam Marine Laboratory

424 MOLLUSCA. CARDIADjE. Pholadomy^a.8. C. semigranulatum.-—Gibbose, transverse, subtriangular, longitudinallystriated, posterior side straight, longitudinally sulcated, and largely granulated.—Sower. Min. Conch, t. cxliv London Clay.9. C. angustatum. — Transversely elongated, thin, rather depressed ; costaetwenty-seven, margin toothed ; retrally truncated, anteally rounded—Sower.Min. Conch, t. cclxxxiii. f. 2 Crag.10. C. edulinum.— Nearly orbicular, convex, slightly oblique, thick ; costaeeighteen, rugose ; slightly truncated retrally Sower. Min. Conch, t. cclxxxiii.1* 3— Crag.1 1. C. turgidum. — Obovate, transverse, smooth, gibbose;longitudinallystriated retrally; edge minutely toothed. — (Brander, 96.)— Sower. Min.Conch, t. cccxlvi. f. 1.— London Clay.12. porulosum— C. Orbicular, retrally obscurely truncated, longitudinallysulcated, with a row of erect, approximate spines united near their points,alternating with each sulcus; sulci terminated by ligulateteeth. Var.spines united through their whole length by a membrane, and their basessunk beneath the edges of the sulci— {Brander, 99.)— Sower. Min. Conch,t. cccxlvi. f. 2—London Clay.13. Cstriatulum.— Orbicular, convex, concentrically striated, posterior sidelongitudinally striated, with a toothed edge—Sower. Min. Conch, t. Dliii. f. 1.—In Lias.14. C. truncatum.— Transversely ovate, gibbose, smooth; posterior sideobliquely truncated, longitudinally sulcated; beaks small— (C. pectinalum,Young, and Brit. Geol. York. 226. t. viii. f.5.)— Sower. Min. Conch, t. Dliii.f. 3.— In Lias.15. C. dissimile— Transversely obovate, gibbose, smooth ; posterior sidebounded by a small rib, longitudinally striated ; front rather straight— Sower.Min. Conch, t. Dliii. f. 2.— Upper Oolite.16. C. decussatum—Cordiform antiquated, longitudinally ribbed, anteriormargin rounded ;posterior side a broad area raised in the middle ; lengthand breadth nearly equal —Mant. Geol. 126. t. xxv. f. 3.Gen. rHOLADOMY^A.--" A transverse, thin, subhyaline,ventricose shell ; the posterior portion short, rounded ;the anterior more or less elongated and gaping ; hingecomposed of an elongated subtrigonal faveola, and a marginalplate in each valve, with a rather short external ligament; the muscular impressions two, indistinct ;the sinusin the impression of the mantel large; the umbones approximated.'"—Sowerbv.1. P. producta.—Transversely oblong, gibbose, with six or seven angularlongitudinal ridges; produced side plain Sower. Min. Conch, t. cxcvii. f. 1.— Inferior Oolite.2. P. obtusa— Transversely obovate, recurved, gibbose, with from seven toten longitudinal, nearly equal, tuberculated ridgesSotver. Min. Conch.I. cxcvii. f. 2— Inferior Oolite.