170 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
which correspond to the ribs on the spire. Aperture oval, posterior angle 
obtuse; outer lip thin, rendered wavy by the spiral cords; columella 
moderately strong, decidedly curved, reflected, and re-enforced by the 
base, provided with a slender fold at its insertion. Length, 2.7; diameter, 
1.3 mm. (Dali and Bartsch.) 
Type in United States National Museum, No. 162762. Type locality, 
San Pedro, California. 
Range. Known only from type locality. 
Odostomia virginalis Dali and Bartsch, 1909 
Bulletin 68, United States National Museum, 160; PI. 18, figs. 7, 7a. 
Shell elongate-conic, thin, semitranslucent. Nuclear whorls obliquely 
immersed in the first of the succeeding turns, above which only the tilted 
edge of the last volution projects, which is marked by three, strongly 
elevated, spiral threads. Post-nuclear whorls well-rounded, moderately 
contracted at the sutures and strongly slopingly shouldered, marked, weak, 
rounded axial ribs, which are best developed near the edges of the shoulder. 
Of these ribs about twenty-four are indicated on the first turn, eighteen 
upon the second to fourth, and twenty upon the penultimate turn. In 
addition to the axial sculpture the whorls are marked between the sutures 
by a number of spiral keels of diverse strength, of which four occur upon 
the first and second, five upon the third, six upon the fourth and the 
penultimate whorl. Of these spiral ridges the second one below the 
summit is the strongest and marks the angle of the shoulder. The junction 
of the ribs and the cords form feeble nodules best shown at the shoulder. 
Sutures strongly constricted. Periphery of the last whorl marked by a 
low cord. Base well-rounded, marked by four, low, broad cords and 
seven exceedingly fine incised lines, the latter about the umbilical area. 
The narrow, strongly incised grooves which separate the cords are crossed 
by numerous fine axial threads, which give them a pitted appearance. 
Aperture oval, slightly effuse anteriorly; posterior angle acute; outer 
lip rendered slightly wavy by the external cords, thin, showing the 
external sculpture within; columella slender, curved, provided with a 
deep-seated fold at its insertion. Length, 3; diameter, 1.1 mm. (Dali and 
Bartsch.) 
Type in United States National Museum, No. 46152. Type locality, 
Todos Santos Bay, Lower California. 
Range. San Pedro, California, to Point Abreojos, Lower California. 
Equals Evalea gracilienta (Carpenter) Keep, 1888, not Odostomia 
gracilienta Monterosoto, 1884. 
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