WEST AMERICAN PYEAMIDELLID MOLLUSKS. 



The following additional specimens have been examined; 



229 



U.S.N.M. 



cat. no. 



206931 



20C9.32 

 105.535 

 20(i933 



No. of 

 speci- 

 mens. 



U.S.B.F. 

 station. 



2901 

 oi2 



Locality. 



Santa Barbara, California 



Off Santa Rosa Island, California. . 



Redondo, California 



San Pedro, California 



do 



San Diego. California 



San Diego (Pacific Beach). Cali- 

 fornia. 



Todos Santos Bay, Lower Cali- 

 fornia. 



Depth, 

 fath- 



Disposition of 

 material. 



Univ. Cal. coll. 

 U.S.Nat.Mus. 

 Univ. Cal. coll. 

 Oldroyd coll. 



U.S.Nat.Mus. 

 Do. 

 Do. 



Do. 



a University of California. 



ODOSTOMIA (AMAURA) MARTENSI Dall and Bartsch. 



Plate 29, fig. 3. 



Odostomia (Amaura) martensi Dall and Bartsch, Proc. U. S. Nat. Mus., vol. 30, 

 1906, p. 361, pi. 15, fig. 5. Odostomia curta Clessin, Mart. Chem. Conch. 

 Cab., 1900, p. 116, pi. 28, fig. 3; not Odostomia curtum Deshayes, An. Sans. 

 Vert. Paris Basin, 1862, p. 551, pi. 19, figs. 9-11. 



Shell ovoid, heavy, yellowish white. Nuclear whorls small, almost 

 completely immersed in the first of the succeeding volutions. Post- 

 nuclear Avhorls increasing regularly and rapidly in size, inflated, 

 subtabulately shouldered at the summit, marked by numerous fine 

 lines of growth and equally abundant, closely placed, wavy spiral 

 striations. These lines of growth and spiral markings give the 

 surface a finely reticulated appearance when viewed under high 

 magnifications. (We have omitted this sculpture in our drawing, 

 which should be considered as an outline sketch only.) Periphery 

 and base of the last whorl decidedly rounded and inflated, marked 

 like the space between the sutures. Aperture large, suboval, slightly 

 efl'use anteriorly, posterior angle acute; outer lip sharp at the edge 

 but thick within; columella very strong, curved, reenforced by the 

 body whorl, from which the slightly reflected edge is separated only 

 by a narrow line. A strong oblique fold, not completely visible when 

 the aperture is viewed squarely, is located a little anterior to the in- 

 sertion of the columella. 



The type has five post-nuclear whorls and measures: Length 5.3 

 mm., diameter 3.1 nmi. Clessin gives the diameter as 1.3, evidently 

 a transposition. He also cites the registration number as 3633G, while 

 it should be 36335. His figure almost represents this species. The 

 type comes from Killisnoo, Alaska, not Japan, as cited by Clessin. 



Subgenus SCALENOSTOMA Deshayes. 

 Scalenostoma Deshayes, Cat. Moll. He de la Reunion, 1863, pp. 58-60. 

 Smooth Odostomias having a strong peripheral keel. 

 Type. — Scalenostoma carinatum Deshayes. 

 2565-Bull. 68—09 16 



