WEST AMERICAN PYRAMIDELLTD MOLLUSKS. 227 



ODOSTOMIA (AMAURA) ILIULIUKENSIS, new species. 

 Plate 29, fig. 4. 



Shell very elongate-conic, heavy, very light yellow. Nuclear whorls 

 small, almost completely obliquely immersed in the first of the suc- 

 ceeding turns. Post-nuclear whorls rather high between the sutures, 

 well rounded with narrowly tabidate summits, marked by fine, re- 

 tractive lines of growth and numerous fine, closely spaced spiral 

 striations. Suture well marked. Periphery of the last whorl well 

 rounded. Base rather prolonged, evenly rounded, marked like the 

 spire. Aperture pear-shaped, posterior angle obtuse; outer lip thin 

 at the edge, thickened within; columella twisted, strongly curved 

 anteriorly, where it is also reflected and reenforced by the base, pro- 

 vided with a low fold at its insertion; parietal wall glazed by a thin 

 callus. 



The type (Cat. no. 159463, U.S.N.M.) was collected by Doctor 

 Dall in 6 fathoms, on mud bottom, ofi^ Iliuliuk Village, Captains 

 Bay, Unalaska, Alaska. It has six and one-half post-nuclear whorls, 

 and measures: Length 9.5 mm., diameter 4.6 mm. Ten additional 

 specimens (Cat. no. 159453, U.S.N.M.) were collected by Doctor Dall, 

 at Eider Cove, Captains Bay, Unalaska, in 25 fathoms on sand bot- 

 tom. Another specimen (Cat. no. 159465, U.S.N.M.), likewise col- 

 lected by Doctor Dall, bears the legend Unalaska, without specific 

 locality. 



ODOSTOMIA (AMAURA) NUCIFORMIS Carpenter. 



Plate 28, fig. 1. 



Odostomia nudformis Carpenter, Ann. Mag. Nat. Hist., 3d ser., vol. 15, 1865, 

 p. 30. Odostomia (Amaura) nuciformis (Carpenter). Dall and Bartsch, 

 Proc. U. S. Nat. Mus., vol. 33, 1907, p. 530, pi. 48, figs. 3, 3a. 



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

 deeply immersed; only half of the last turn is seen in tilted position 

 when viewed from above. Post-nuclear whorls increasing rapidl}'' in 

 size, well rounded, having their summits closely appressed to the pre- 

 ceding whorl. Suture moderately well impressed. Periphery and 

 base of the last whorl well rounded. Aperture rather large, ovate, 

 white within; posterior angle jacute; outer lip moderately thin at the 

 edge, thicker within; columella short, strongly curved, with a strong 

 oblique fold at its insertion; reenforced by the attenuated base; parie- 

 tal wall covered by a thin callus. 



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

 ington. It has five post-nuclear whorls which measure: Length 7.7 

 mm., diameter 4.4 mm. 



