History of British animals - University of Guam Marine Laboratory

im MOLLUSCA. SOLENID^E. Panop.ea-1115— Mya arctica, Fab. Fauna Groen. 407. — Curious Muskle.ccccxxvi.— Chamse-pholas angusta, List. Conch, t. Solen minutus, Linn-Syst.Cordiner's Ruins, Plate No. 24. f. A.— Solen minutus, Mont. Test. Brit.53. t. i. f. 4.— Hiatella minuta, and H. oblonga, Turt. Biv. Brit. 24. t. ii.f. 12, 13—Anatina arctica, ib. 49. t. iv. f. 7, 8.— Roots of fuci.This species, when young, has the spinous ridges very distinct ; and, whennot imbedded in stone, it adheres by a byssus. When old, the spinous ridgesdisappear, and then in size, and other circumstances, it so exactly resemblesthe preceding, as to leave little room for suspecting a specific difference. TheMytilus prcecisus of Montagu, (Test. Brit. 165. t. iv. f. 2.) seems to be a varietyin which the anterior end is truncated, and very short, and the beaks elevated; while the M. plicatus of the same author only differs in the beaks beingsmall and slightly incurvated.EXTINCT SPECIES.1. H. sulcata.—Beak nearly terminal; both extremities rounded; shellthin, concentrically sulcated, the ridges large retrally, formed by the unionof two or more ribs ; closely and obsoletely striated longitudinally, thestriae consisting of minute tubercles Not uncommon in the CarboniferousLimestone of the Forth Coal-Field.Gen. CXXXVIII. PANOPtEA.— Shell transverse, unequallyopen at the sides ;a single conic tooth in each valve, withan adjoining short compressed callus, to which an externalisligament attached.575. P. Aldrovandi.— Truncated at both extremities, andcoarsely wrinkled transversely.Chama Glycimeris, List. Conch, t. ccccxiv.— Mya Glycimeris, Dan. Brit.Shells, t. cxlii—P. Gly. Turt. Biv. Brit. 42.— English coast, rare.Length about 4 inches, breadth 8 ; coarse and thick ; a series of wrinklesbehind the teeth. One specimen from the Dogger-bank occurred to Mr Donovan,and a fragment of a valve found on the beach at Teignmouth, by DrTurton, are the only British examples of this shell, which is sometimes foundon the coast of France and Spain.myam:.Gen. CXXXIX. MYA. — Equivalve, transverse, gaping;hinge with a single projecting dilated tooth in the rightvalve, for supporting the ligament, with a pitin the left.576. M. truncata.— Shell rounded anteally, abruptly truncatedretrally ;the ventral margin nearly straight.Concha hevis, List. An. Ang. 191.— Conch, t. ccccxxviii.— M. trun. Linn.Syst. Nat. i. 1112. Penn. Brit. Zool. iv. 78. t. xli. f. 14. Mont. Test.Brit. 32. Turt. Biv. Brit. 31 Common near low water-mark, lodgedin sand or gravel.