286 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
pit is marked by five fine incised spiral lines, while the space between the 
fourth and fifth pit is also divided by a fine spiral line, which is a little 
nearer the fourth pit than the fifth. Sutures rendered rather conspicuous 
by the very narrowly shouldered summit of the whorls. Periphery of the 
last turn well-rounded. Base short, well-rounded, marked by 15 incised 
spiral lines, which gradually diminish in spacing and strength from the 
periphery to the umbilicus. The six at the umbilical region are very fine 
and very closely crowded. The rest increase regularly in size and spacing, 
excepting the fourth anterior to the periphery, which is much finer than 
the third and fifth. Aperture subquadrate; posterior angle obtuse; outer 
lip thin; inner lip almost vertical, reflected over and appressed posteriorly 
for about one-third of its distance to the base; parietal wall covered by a 
thin callus. 
Type in United States National Museum, No. 340933. Type locality, 
San Clemente Island, California. It has nine and a half whorls and 
measures, length, 7.6 mm.; diameter, 2.3 mm. This species is nearest 
related to Turbonilla (Pyrgolampros) dora Bartsch. 
Subgenus Salassiella (see pp. 152-153) 
Odostomia oenoa Bartsch, 1927 
Proceedings of the United States National Museum, 70: 12; PI. 2, fig. 3. 
Shell rather large, conic, grayish white. Nuclear whorls decollated. 
Postnuclear whorls rather high between the summit and the periphery, 
slopingly shouldered at the summit, marked by 24 somewhat retractively 
slanting, axial riblets which are separated by shallow intercostal spaces, the 
latter being a little narrower than the riblets. These riblets extend from 
the summit to the periphery while from the periphery basally they gradu¬ 
ally evanesce. Suture rather strongly constricted. Base moderately long, 
well-rounded. Aperture oval; posterior angle obtuse; columella provided 
with a strong oblique fold which is situated a little anterior to the insertion 
of the columella; parietal wall covered by a rather thick callus. 
Type in United States National Museum, No. 362441. Type locality, 
in 6 fathoms off Deadman Island, San Pedro, California. It has almost 
seven whorls and measures, length, 7 mm.; diameter, 2.1 mm. 
Subgenus Chrysallida (see p. 155) 
Odostomia tremperi Bartsch, 1927 
Proceedings of the United States National Museum, 70: 14; PI. 3, fig. 1. 
Shell very elongate-conic, bluish white. Nuclear whorls at least two, 
smooth, forming a depressed helicoid spire, the axis of which is obliquely 
immersed in the first of the succeeding turns above which a little less than 
1 584 ] 
