History of British animals - University of Guam Marine Laboratory

Spondylus. MOLLUSCA. ARCADE. 397Gen. SPONDYLUS.—Shell eared, beak of the under valveproduced, with an exposed oblique truncation, having alongitudinal groove ; hinge of two teeth, with an intermediategroove for the reception of the internal ligament.1. S. radula.—Mr Parkinson refers to a shell of this species (of Lamark,from Grignon), which he suspects to have been from "Worcestershire. " It isslightly eared, and the inferior valve is marked with rough longitudinal stria?.It is rough, oblique, and of an oval orbicular form. The stronger and mostraised of the striae of the lower valve have small spinous squama? placed atabout half an inch distant, these striae being separated by from six to ninesmall granular striae."Gen. PLICATULA.— Shell destitute of ears ;narrow at thebase ; the opposite margin rounded and plaited ; beaks unequalentire ;teeth two, with an intermediate pitfor thesubinternal cartilage.1. P. spinosa.— Ovate depressed, spinose; margin entire; spines adpressed ;smallest on the deep valve— Harpax, Park. Org. Rem. iii. 221. t. xii, f. 14.—P. spin. Sower. Min. Conch, t. ccxlv—In Lias.2. P. pectinoides — Oblong, ovate, curved, gibbose when old ;longitudinalridges numerous, furnished with depressed spines ; free valve externally concave.—Sower. Min. Conch, t. ccccix. f. 1.— Chalk Marl.3. P. infiata — Suborbicular, gibbose, rather smooth, furnished with a fewridges and depressed spines ; both valves convex. P. spinosa, Mant. Geol.Suss. 129. t. xxvi. f. 13, 1G, 17- P. inf. Sower. Min. Conch, t. ccccix. f. 2.—Chalk Marl.ARCADiE.Gen. XCVIII. ARCA.— Shell transverse ; beaks remote ;teeth numerous, enlarging from the middle, but withoutlateral teeth ;ligament external.400. A. Noce.— Shell oblong, decussated in a punctured manner,angular at the anterior side, with the upper margin transverselyelongated, sinuous and open.Musculus striatus, List. Conch, t. ccclxviii. Borl. Corn, cclxxvii. t. 28.f. 16 A. Nose, Linn. Syst. 1140 i. A. tortuosa, Penn. Brit. Zool. iv.97 A. Noae, Don. Brit. Shells, t. clviii. f. 1, 2. Mont. Test. Brit. J 39.Turt. Biv. Brit. 166 Western coast of England and Guernsea, rare.Shell about half an inch long, a little more in breadth ; rufous, with darkzigzag bands, rounded at the longest end, angular at the other, to which theincurved beaks approximate.401 .K.fusca.— Shell oblong, decussated, angular at the ante-