History of British animals - University of Guam Marine Laboratory

398 MOLLUSCA. ARCADE. Arc arior side, with the upper margin shorter, straight, and nearlyclosed.Balanus Eellonii, List. Conch, t. ccvii.— Musculus striatus, Borl. Corn.277- t. xxviii. f. 15—Area Nose var. Don. Brit. Shells, t. clviii. f. 3.A. fusca, Mont. Test. Brit. Sup. 51. t. 4. f. 3. Turt. Biv. Brit. 167Southern coasts of England, and Frith of Forth, rare.This species nearly resembles the last, of which it isperhaps only a variety.It differs, however, in being narrower, the beaks more lateral, a greaterconvexity, straighter margin, and finer decussations.402. A. tetragona.— Shell rhombic, with granular decussations,and an oblique longitudinal rib, open at the margin.Larnk. Hist. vi. 37- Turt. Biv. Brit. 167- 1. 13. f. 1—At the Calves,west of Ireland, Dr Turton." Shell |ths of an inch long, and an inch broad, of an oblique square figure,tumid at the beaks, from which proceed a nearly central rib, to the angularpoint of the opposite margin ; hinge not quite straight, in consequence of themarginal slope colour whitish-brown, inside ; white, with a purple blotch atone end." Turt.403. A. barbata.— Shell oblong, with longitudinal beardedribs, decussated by minute striae the ;margin straight and nearlyclosed.Brown, Wern. Mem. ii. 512. t. xxiv. f. 3—A. reticulata, Turt. Biv. Brit.168. Found in Loch Strangford, by Dr Magee.Length half an inch, breadth one inch ; shell white ;cuticle chesnut ; ribsabout twelve, nearly equidistant and flat ; inside striated longitudinally,margin finely crenulated.404. A. lactea.— Shell oblong, decussated and bearded, angularat the anterior end, and slightly open at the margin.Pectunculus exiguus, List. Conch, t. cccxxxv—A. lac. Linn, Syst.i. 1141.—A. barbata, Penn. Brit. Zool. iv. 98. t. lviii. f. 59.—A. lac. Mont. Test.Brit. 138.— A. perforans, Turt. Biv. Brit. 169. 1. 13. f.2,3 Differentparts of the coast, but not common.Length half an inch, breadth three quarters shell ; white, with a brownpilose cuticle ; ribs numerous, fine, crossed by the wrinkles of growth ; intersticespunctured inside ; white, margin plain.EXTINCT SPECIES.1. A. subacula. Gibbose ; margin an obtuse scalene triangle, deeply plaited; breadth greater than the length ; surface longitudinally striated.— Sower.Min. Conch, t. xliv. Upper fig—In Chalk Marl.2. A. carinata— Very convex parallelopipedal, anterior side flattish, separatedby an acute angle, truncated at nearly a right angle ; posterior siderounded ;surface longitudinally ribbed—Smvcr. Min. Conch, t. xliv. Lowerfigure In Green Sand.3. A. Branderi.— Transversely elongated, rhombic, gibbose, finely decussated; beaks distant ; longitudinal striae strongest teeth numerous ; ;edge internallyentire—Soiver. Min. Conch, t. eclxxvi—London Clay.4. A. appendiculata — Transversely elongated, rhombic, gibbose, decussated ;beaks rather distant ; two oblong appendages upon the space between the