WEST AMERICAN PYRAMIDELLID MOLLUSKS. 225 



temperature of 41°. 8. Another specimen (Cat. no. 109454, U.S.N.M.) 

 comes from Sea Horse Islands, Arctic Ocean. Two lots (Cat. no. 

 168807, U.S.N.M.) four specimens collected in 15 fathoms off Icy 

 Cape, Arctic Ocean, and a single specimen (Cat. no. 168808, U.S.N.M.), 

 in 7 to 15 fathoms, from the same locality. Eight additional speci- 

 mens were dredged at U. S. Fish Commission station 3306, off Bristol 

 Bay, Bering Sea, in 33 fathoms, bottom temperature 38°. 9. 



ODOSTOMIA (AMAURA) AVELLANA Carpenter. 



Plate 28, fig. 3. 



Odostomia (? var.) avelhma Carpenter, Anu. Mag. Nat. Ilist., 3d ser., vol. 15, 

 1865, p. 30. Odostomia (Amaura) nuciformis avcllana (Carpenter) Dall 

 and Bartsch, Proc. U. S. Nat. Mus., vol. 33, 1907, pp. 530, 531, pi. 48, figs. 

 1, lo. 



Shell large, elongate-ovate, yellowish to milk white. Nuclear whorls 

 deeply vertically immersed; only part of the last volution is visible 

 when viewed from above, their axis evidently being at a right angle 

 to the axis of the later whorls. Post-nuclear whorls increasing rapidly 

 in size, early ones well rounded, later ones less so, their summits being 

 closely appressed to the preceding whorl. Suture well impressed, 

 simple. Periphery and base of the last whorl well rounded, the latter 

 somewhat elongated. Aperture large, ovate, somewhat effuse ante- 

 riorly, milk-wiiite within; posterior angle acute; outer lip thin at the 

 edge, thick within; columella short curved; reenforced partly by the 

 attenuated base, having a strong oblique fold at its insertion; parietal 

 wall covered by a moderately strong callus. 



The type (Cat. no. 15517&, U.S.N.M.) comes from Neah Bay, Wash- 

 ington. It has five post-nuclear whorls and measures: Length 8.3 

 mm., diameter 4.3 mm. 



ODOSTOMIA (AMAURA) MORATORA, new species. 



Plate 30, fig. 7. 



Shell elongate-ovate, imperforate, yellowish white. Nuclear whorls 

 decollated. Post-nuclear whorls strongly rounded, moderately con- 

 tracted at the sutures, narrowly flatly shouldered at the summit; 

 marked by strong lines of growth and subobsolete fine spiral lira- 

 tions which lend the surface a somewhat reticulated appearance. 

 The spaces between the feeble lirations are marked by numerous 

 very fine spiral striations. Periphery of the last whorl and base 

 inflated, strongly rounded, marked like the spire. Aperture oval, 

 posterior angle obtuse; outer lip thin; columella stout, oblique, 

 revolute, provided with a strong fold a little below its insertion. 



The type (Cat. no. 207261, U.S.N.M.) was dredged by the U. S. 

 Bureau of Fisheries at station 3164, rocky bottom, temperature 

 48°. 5, in 61 fathoms, off Point Reyes, California. It has six post- 

 nuclear whorls and measures: Length 9.5 mm., diameter 4.9 mm. 



