OCR Text |
Show 1891.] MR. E. A. SMITH ON SHELLS FROM ADEN. 433 Bruguiere (Encycl. Meth. pi. 311. f. 5), and Bonanni (Mus. Kirch. ii. pi. xvii. f. 129). The last-mentioned figure was described by Gmelin under the name of Cardium amboinense (Syst. Nat. p. 3255). The specific name I propose to retain for this form, as it is older than either P. subauritus or P. pectiniformis of Lamarck. Martens quotes it from Mergui. The external colouring of these two species is very similar, but there is a feature within the valves which, in addition to the broader sulci, seems to indicate that the species are distinct. I refer to the colouring of the margin of the hinge-plate below the teeth. This is almost invariably of a rich brown or reddish-brown colour. On the other hand, in P. amboinensis, the species with broad ribs and narrow sulci, this part apparently is never entirely coloured, but occasionally a small brown mark is observable at one or both sides. In the series of specimens in the British Museum, the differences are quite noticeable and the two forms are readily separable. 256. LIMOPSIS FORSKALII, A. Adams. Hab. Japan. The single valve described by Adams is small in comparison with some of the specimens obtained at Aden by Major Yerbury. The largest is 25 millim. long, 25^ from the umbones to the ventral margin, and 13^ through the valves. The epidermis which remains towards the outer margin is closely pilose and yellowish. The interior of the dead valve from Japan was described as pale red; in the Aden specimens it is rich brown, paler or even whitish at the circumference, and in the middle of the valves the rich brown colour is more or less clouded with a thin whitish callus, which, however, does not cover the muscular scars or the pallial line. Hinge-teeth about 28 in number. 257- PINNA BICOLOR, Chemnitz. Hab. Red Sea (Chemnitz) ; Malacca (Reeve) ; Mergui (Martens). Two valves from Aden exhibit the coloration described by Chemnitz; one specimen agrees with Reeve's figure (Conch. Icon. f. 17), and another example is almost entirely of a uniform whity-brown colour, with the elevated ridges towards the apex obscurely tinted olive-brown. The elevated scales upon the feeble ridges are few and far apart. 258. PINNA SERRA, Reeve. Hab. Queensland. 259. PINNA RIGIDA, Dillwyn ? Hab. West Indies. One valve only. 260. MALLEUS ALBUS, Lamarck. Hab. Philippine Islands. |