WEST AMERICAN PYRAMIDELLID MOLLUSKS. 



Examination of the following specimens has been made : 



167 



U.S.N.M. 

 cat. no. 



60905 

 162774 



206901 

 206902 

 162773 



No. of 

 speci- 

 mens. 



11 

 100 

 190 

 9 

 11 

 6 

 1 



Locality. 



San Diego, California 



San Pedro, California 



do 



San Pedro Bay, California. 

 Terminal Island, California 

 Pacific Beach, California... 

 Arch Beach, California 



Disposition of 

 material. 



U. S. Nat. Mus. 



Do. 

 Oldroyd coll. 

 U.S. Nat. Mus. 



Do. 



Do. 

 Univ. Cal. coll. 



ODOSTOMIA (CHRYSALLIDA) SANCTORUM, new species. 



Plate 18, fig. 1. 



Shell elongate-ovate, light yellow. Nuclear whorls smooth, deeply 

 obliquely immersed in the first of the succeeding turns, above which 

 only the tilted edge of the last volution projects. Post-nuclear whorls 

 moderately rounded, very slightly contracted at the sutures, moder- 

 ately shouldered at the summits, marked by a strongly incised spiral 

 line a little distance below the summit, and three feeble ones of which 

 one is at the periphery, the other two dividing the space between 

 those two into three equal areas. These lines, excepting the one near 

 the summit, which is strong tliroughout, are best developed on the 

 early wdiorls. In addition to the spiral sculpture, the whorls are 

 marked between the sutures by strong lines of growth and indica- 

 tions of feeble axial ribs which tend to render the early whorls some- 

 what nodulous. Sutures strongly impressed. Periphery of the last 

 whorl strongly inflated. Base well rounded posteriorly, slightly at- 

 tenuated anteriorly, marked by six well incised equal and subequally 

 spaced spiral grooves which are crossed by many slender axial 

 threads. Aperture large, oval, effuse anteriorly; posterior angle 

 acute; outer lip thin, showing the external sculpture within; colu- 

 mella moderately strong, curved, reflected, reinforced by the base, 

 provided with a deep-seated fold. 



The type and tliree specimens (Cat. no. 

 from Todos Santos Bay, Lower California, 

 one-half post-nuclear whorls and measures: 

 ter 1.3 mm. Cat. no. 206803, U.S.N.M. 

 Point, Lower California. 



46490, U.S.N.M.) comes 



The type has four and 



Length 2.5 mm., diame- 



three from San Hipolito 



ODOSTOMIA (CHRYSALLIDA) SAPIA, new species. 

 Plate 18, figs. 3, 3a. 



Shell oval, semitranslucent. Nuclear whorls small, deeply obliquely 

 immersed in the first of the succeeding tm-ns, above which only the 

 tilted edge of the last volution projects, which is marked by five 

 slender spiral tlireads. Post-nuclear whorls amply rounded, slightly 



