| OCR Text |
Show 820 ON MARINE SHELLS FROM THE ANDAMAN ISLANDS. [Nov. 5, upper valve slightly carinate from the umbo to the posterior margin, the keel terminating a little above the middle, rather smooth, finely concentrically striated by the lines of growth and sulcated at the umbo; covered with a thin greyish epidermis, a trifle laminated towards the margin ; and from the umbo about four rather indistinct ridges radiate down the posterior half of the valve, becoming obsolete about the middle of it, and again conspicuous in some specimens at the margin : lower valve vastly larger than the other, very deeply and widely concentrically sulcated; sulci fine and close together at tbe umbo; ridges between the sulci very thick and prominent, thicker anteriorlv than at the opposite extremity, and terminated in front by a sulcus or depression extending from the umbo downwards at a little distance from the margin, which is raised, taking the form of a stout marginal ridge which terminates the beaked end of the valve ; transverse grooves finely striated in the same direction : one tooth in each valve, that of the upper bifurcate; pallial sinus small; anterior scar sub-rotund^, posterior more elongate. Diam. 14 mill., length 10, thickness 8 2 ; the lower valve of another larger specimen is 23^ mill, in diameter and 16 long. For many years several lower valves of this species have been in the Brit-sh Museum with the locality "Jack's Island, South Sea," attached to them. Others were presented by J. B. Jukes, Esq. in 1845, who dredged them at Port Essington in 7 fathoms, from a muddy bottom ; and two specimens in the Cumingian Collection are from the same place. The form, the coarse costae (which, however are sometimes rather close together), and the anterior raised and beaked margin of the lower valve well distinguish the species. 71. CRASSATELLA RADIATA, Sowerby; Reeve, Conch. Icon.i. fig. 12. Hab. Singapore. 72. ARCA(SCAPHARCA)MYRISTICA, Reeve, Conch. Icon. ii. sp. 42. Hab. Philippine Islands (Cuming). 73. PECTEN ALBOLINEATUS, Sowerbv, Thesaurus Conch, pl. 14 figs. 69, 70. " ^ Hab. Philippine Islands. 74. ISOGNOMON SAMOENSIS, Baird. Perna (Isognomon) samoensis, Baird, ' Cruise of the Curacoa ' p. 454, pl. 42. fig. 8. Hab. Tutuila, Samoa Islands. BRACHIOPODA. 75. LINGULA HIANS, Swainson ; Sowerby, Thesaurus, i. pl. 67. Hab. China. Capt Wilmer's notes on this species are as follows :- • It lives in mud or sandy clay at low-water mark, the shell being mned about a foot from the surface. It is very easily alarmed, and |
