16 Dall and Bartsch The Pyramidellidce. 



Aperture subovate, outer lip [fractured], showing five internal, spiral 

 lirations the middle one of which is stronger than the rest; columella 

 short, twisted and revolute, having a strong oblique fold near its insertion. 

 The type is number 58,015 of the collection of the Academy of 

 Natural Sciences of Philadelphia and was collected by 8. Archer at 

 Singapore. It has six and one half postnuclear whorls and measures: 

 long., 2.7 mm.; diam., 1.1 mm. 



Odostomia (Evalina) americana sp. nov. 



Shell elongate-conic, subdiaphanous to milk-white. Nuclear whorls 

 quite large, at least two, about three-fourths obliquely immersed. Post- 

 nuclear whorls rather broad between the sutures, well rounded, faintly 

 shouldered at the summit, ornamented with depressed, rounded, rather 

 broad axial ribs about eighteen of which occur upon the second, twenty 

 on the third and eighteen upon the penultimate whorl. The ribs are best 

 developed near the summits of the whorls and scarcely extend to the peri 

 phery. Spiral lirations low, rounded, subequal, about twelve occur be 

 tween the sutures upon the third and the penultimate whorls. These 

 spiral lirations like the axial ribs appear strongest near the summits of the 

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

 ornamented by about eleven lirations which are similar in character to 

 those between the sutures but much less strongly expressed. Aperture 

 rather broad, suboval, somewhat effuse anteriorly, posterior angle acute; 

 outer lip thin; columella short, somewhat curved, strongly revolute an 

 teriorly, having a weak oblique fold near its insertion. 



The type, No. 168,718 U. S. National Museum collection, and nine 

 specimens come from San Pedro, California. It has five postnuclear 

 whorls and measures: long., 2.9mm.; diam., 1.3mm. Another specimen, 

 168,719, comes from San Diego, and two others, No. 168,720, from Sta. 

 Catalina Id., California. Ten were determined for Mrs. Oldroyd from 

 San Pedro. 



