History of British animals - University of Guam Marine Laboratory

Pecten. MOLLUSCA. BIVALVIA. 383PECTENID^.Gen. XCIV. PECTEN. Scallop.—Shell suborbicular ;beaks approximate;ligament internal, seated in a triangularcavity,a byssus issuing under the ear of the right valve ;foot small, pedunculated;mouth with branched tentacula.* Ears of the shell equal, or nearly so.— 371. P. maximus. — The left or upper valve flat, depressedtowards the beak, the ribs rounded and striated longitudinally.List. An. Ang. 184. Conch, t. clxiii.— Ostrea maxima, Linn. Syst.i.1144.—P. max. Penn. Brit. Zool. iv. 99. t. lix. f. 61. Mont. Test.Brit. 143. Turt. Bev. 207 Gregarious on many parts of the coast.Length about 5 inches under valve ;whitish, upper valve variegated withbrown; ribs 12 to 16, longitudinally grooved and transversely striated.Dredged and used as food ; it is said by old fishermen, to be taken in greatestquantity after a fall of snow.— 372. P. JacobcBus. — The upper valve flat, depressed towardsthe beak, the ribs rounded and destitute of longitudinal strise.P. magnus, List. Conch, t. clxv.—Ostrea Jac. Linn. i.Syst. 1144—P.Jac. Penn. Brit. Zool. iv. 100. t. lx. f. 62. Mont. Test. Brit. 144.Turt. Biv. 208.—On the coast of England, rare.Length about 3 inches ;lower valve white, upper valve rufous ; ribs about16, in the upper valve rough, subquadrangular, with a few longitudinalgrooves, the interstices nearly smooth ;the ribs in the lower valve rounded,and, together with the grooves, transversely striated.— 373. P. opercularis.— The left valve convex; ribs rounded,nearly smooth.P. tenuis, List. An. Ang. 185. Conch, t. cxix.— P. oper. Linn. Syst.i.1147-— P. subrufus, Penn. Brit. Zool. iv. 100. t. lx. f. 63 P. oper.Mont. Test. Brit. 145. Turt. Biv. Brit. 209. and P. subrufus, p. 210.—Common on oyster beds.Breadth from 2 to 3 inches ; coloured plain or variegated ; ribs about 18,the whole shell obsoletely striated longitudinally, and finely striated transversely,especiallyin the furrows.374. P. lineatus.— The left valve convex ;a red line alongthe rough ridge of each rib.(Da Costa, Brit. Conch. 147. t. x. f. 8.) Pult. Dorset. 36—Ostrea lin.Don. Brit. Shells, t. cxvi Southern coast of England.This shell is smaller than the preceding, the sides do not rise quite sohigh towards the ears ;and the ribs are much finer. It seems to have beenfirst noticed by Dr Pultney. Dr Turton considers it as a variety of P. opercularis.