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Show 1881.] ' LIGHTNING' A N D 'PORCUPINE' EXPEDITIONS. 937 rounded on each side, gently curved in front, straight at the beak small and pointed, recurved towards the anterior side ; umbones very prominent; cartilage-pit oval, minute, placed obliquely under the beak : hinge-line straight: hinge-plate narrow : teeth consisting of only a slight lateral on the posterior side : inside glossy: scars indistinct. L. 0*25, B. 0*3. 'Porcupine' Exp. 1870 : Atl. St. 16 (a single valve and a fragment) . Distribution. Bay of Biscay ('Travailleur' Exp.), a living and perfect specimen ; 733 fms. 2. NE^ERA SUBTORTA, G. O. Sars. N. subtorta, G. O. Sars, Moll. reg. arct. Norv. p. 87, t. 6. f. 6, a-'Lightning' Exp. St. 1, 3. 'Porcupine' Exp. 1869: St. 62. DistriBution. Spitsbergen, Norwegian arctic Expedition, Finmark, Kara Sea ; 30-123 fms. Fossil. British North-Polar Expedition, lat. 82° 33'; 40 ft. 3. NE^RA SULCIFERA1, Jeffreys. (Plate LXX. fig. 10.) S H E L L obliquely oval, convex, thin, semitransparent, rather glossy: sculpture, irregular lines of growth, which become curved strise on the upper part of the anterior side ; rostrum short and broad-ish, separated from the rest of the shell by a furrow, as if pinched up : it has a single ridge or keel in the middle, extending from the beak to the posterior end : colour white : epidermis fibrous : margins rounded on the anterior side and in front, terminating on the posterior or rostral end in a blunt curve, and sloping at the back on each side of the umbo : Beaks blunt, slightly incurved ; umbones prominent: cartilage-pit forming a small narrow and oblique slit: teeth as in N. truncata: inside glossy, exhibiting there tbe underside of the furrow as a ridge : scais indistinct. L. 0*25, B. 0*35. 'Porcupine' Exp. 1869: St. 40. 1870: Atl. 9, 13, C. Sagres, 27, 28. DistriBution. Bay of Biscay ('Travailleur' Exp.); 552-628 fms. This species differs from N. subtorta in being somewhat broader and not twisted, and in having a blunter rostrum, which is marked by a ridge in the middle and separated by a furrow from the rest of the shell. The last characters serve to separate it also from N. obesa. 4. NE^ERA OBESA, Loven. N. obesa, Lov. Ind. Moll. Scand. p. 48; G. O. Sars, Moll. reg. arct. Norv. p. 86, t. 6. f. 4, a-c. ' Porcupine' Exp. 1869 : St. 37 (young, living). 1870 : Atl. 1, 3. DistriBution. Spitzbergen, Norway, Skager Rack and Cattegat, Azores, N.E.America, Catania?; 20-1000 fms. Fossil. Pliocene: Calabria? 1 Marked with a furrow. |