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Show 1878.] ' L I G H T N I N G ' A N D ' P O R C U P I N E ' EXPEDITIONS. 403 valve gibbous ; lower valve somewhat compressed ; it is rather solid, opaque, and lustreless : sculpture, slight and fine longitudinal striae, which radiate from the beak (50 to 60 in a larger, and half that number in a smaller specimen) ; these are crowded at the sides, and are occasionally or partially intervenient; concentric marks of growth distinct, besides numerous intermediate and irregular lines: ccecal tubuli white, minute, and close-set: colour white, with an ochreous tinge : margins curved in front, or slightly indented there in the middle of the upper valve, more or less truncated at the sides, rounded and somewhat shouldered behind in the lower valve : beak extended or produced : foramen large, circular, complete, thickened, and reflected at the lower side: deltidium long and narrow, slightly grooved across : hinge-plate thick and broad: teeth in the upper valve short and incurved : loop narrow, keyhole-shaped, attached to the hinge by short crura, which terminate halfway in small blunt spurs, obtusely angular below in the smaller, and flexuous in the larger specimen: inside smooth, slightly grooved lengthwise in the smaller specimen, to correspond with the outside striae, and having the inner edges of the larger specimen thickened and notched or crenate, as in Astarte sulcata and in many species of Venus, Nucula, and other genera. L. 1*05, B. 1 (larger specimen); L. 0*65, B. 0*55 (smaller specimen). Hab. Off the coast of Portugal, in 500-600 fathoms (Kent). Of this new and interesting species Mr. Kent dredged two specimens and a couple of valves, which he presented to Mr. Davidson and myself. I at first thought it might be the T. orbiculata of Seguenza (Mem. Soc. Ital. Sc. Nat. t. i. no. 4, 1865, p. 7, tav. ii. f. 14- 16), judging from the description and figures; but he has lately, with his usual courtesy, sent me for inspection the type of his species. This shows that the smaller valve is not shouldered (so as to give the shell a squarish outline), and that the striae are much finer and more numerous than in T. subquadrata. He, indeed, now suspects that his species may be the young of a large species, such as T. ampulla or T. grandis; but that species is not striated lengthwise. I should be inclined to refer Seguenza's species to the variety sphenoidea of T. vitrea. The form of the skeleton or apophysis depends to some extent on the shape of the specimen in a species so variable as T. vitrea. 5. TEREBRATULA VITREA, Born. (Plate XXII. fig. 5.) Anomia vitrea, Born, Test. Mus. Caes. Vind. p. 104. 'Porcupine' Exp., 1870: Atlantic, St. 13, 220 f. ; 16, 994 f. ; 17a, 740 f.; 24, 292 f. ; 25, 374 f. ; off Cape Sagres, 45-58 f. ; 26, 364 f.; 27, 322 f.; 28, 304 f. ; 29, 227 f.; Mediterranean, 45, 207 f.; Capo de Gata, 40-69 f.; 55, 1456 f. ; Adventure Bank, 92 f. Atlantic coast of Spain to the Adriatic and iEgean: depths 5-310 f. , ,. . B O D Y clear white and gelatinous : mantle lining the valves, and 26* |