96 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
second and the penultimate turn between the sutures. The first of these 
spiral cords is at the summit, which it renders feebly crenulate. The spaces 
inclosed between the axial ribs and spiral cords are rectangular pits, just 
a trifle longer than broad, their long axes corresponding to the spiral 
sculpture. In addition to the above sculpture the entire surface of the 
spire is marked by exceedingly fine, closely spaced, spiral striations and 
axial lines of growth. Suture moderately impressed. Periphery of the 
last whorl marked by a sulcus as wide as those which separate the spiral 
cords on the spire. Base strongly rounded, feebly produced anteriorly, 
marked by nine, equal and equally spaced, somewhat flattened spiral cords, 
which are about as wide as the spaces that separate them, and the fine 
sculpture noted for the spire. Aperture broadly ovate; posterior angle 
obtuse; outer lip thin, showing the external sculpture within; inner lip 
strongly curved, slightly reflected over and appressed to the base; parietal 
wall covered with a thick callus. Length, 3 ; diameter, 1.7 mm. (Bartsch.) 
Type. Cotypes United States National Museum, No. 4338. Type lo¬ 
cality, Puget Sound, Washington. 
Range. Port Etches, Alaska, to Trinidad, California. 
Alvania cosmia Bartsch, 1911 
Plate 82, fig. 4 
Proceedings of the United States National Museum , 41:352; PI. 31, fig. 4. 
Shell small, elongate-ovate, white, semitranslucent. Nuclear whorls 
one and one-half, marked by four, moderately strong, spiral lirations, 
which are separated by strongly impressed lines. Post-nuclear whorls ap¬ 
pressed at the summit, strongly, slopingly shouldered, the shoulder ex¬ 
tending from the summit to the anterior termination of the posterior 
third between the sutures, marked by two, strong, nodulose, spiral keels, 
of which the first is situated on the angle of the shoulder, while the second 
is about as far posterior to the suture as the first is anterior to the summit. 
In addition to these spiral keels, the whorls are marked by moderately 
strong, axial ribs which become enfeebled on the shoulder and anterior to 
the second keel. Of these ribs, 16 occur upon the first and second, and 
18 upon the penultimate turn. The spaces inclosed between the spiral 
keels and axial ribs are large, deeply impressed, squarish pits, while their 
junctions form cusplike tubercles. Suture strongly channeled. Periphery 
of the last whorl marked by a strong, sublamellar, spiral keel. Base 
moderately long, marked by three spiral keels, which grow successively 
weaker and closer spaced from the periphery to the umbilical area. The 
broad spaces between the spiral keels are marked by slender, axial lines 
of growth. Aperture broadly ovate; posterior angle obtuse; outer lip re- 
f 698 1 
