CLASS GASTROPODA 
209 
Shell like M . lirulata; small, thin, whitish-ashy, spotted irregularly 
with tawny-olive, or punctulate; with nuclear whorls two, smooth, thick, 
tawny, with mammillate apex; with normal whorls three, thick tabulate 
with rectangular sutures ; with three acute, equidistant carinae on the spire; 
with a fourth peripheral; with interstices spirally striate; on the spire and 
around the base radially thickly striate; with base subrotund, arcuate with 
about nine distant lirulae; with large umbilicus, funnel-shaped, within 
sometimes sculptured with few spiral striae; with aperture subrounded, 
with wall hardly touching ; operculum with about six small whorls, with 
subelevate sutures. (Translation.) 
Tyte in United States National Museum. Type locality, Santa Bar¬ 
bara, California. 
Range. Bodega Bay to Coronado Islands. 
Margarites smithi Bartsch, 1927 
Proceedings of the United States National Museum, 70:32. 
Shell minute, rather elevatedly helicoid, white. Nuclear whorls one and 
a half, well-rounded with a carina about one-third of the distance between 
the summit and the suture, anterior to the summit. Postnuclear whorls 
well-rounded, marked by the continuation of the nuclear carina, which 
forms a rather strong cord and a slender cord about midway between this 
and the summit, and two strong cords which divide the space between the 
carina and the suture into equal spaces. Between these three cords a lesser 
one is present. From the third cord, which almost marks the periphery on 
the last whorl, the base curves gently to the rather open umbilicus. The 
base is marked by spiral cords, which increase steadily in strength from 
the periphery to the umbilical angle; the last five are very strongly 
developed. The umbilical wall appears to be free of sculpture, excepting 
incremental lines. The spire and base of the shell are marked by strong 
incremental lines, which in crossing the base form slight riblets between 
the spiral cords. Aperture, oval; posterior angle, obtuse; outer lip, thin; 
peristome complete; operculum multispiral, horny. (Bartsch.) 
Type in United States National Museum, No. 340814. Type locality, 
China Point, Monterey, California. It measures, altitude, 1.6 mm.; greater 
diameter, 1.7 mm. 
Margarites althorpensis Dali, 1919 
Proceedings of the United States National Museum , 56:365. 
Shell small, solid, trochiform, nacreous white, with a minute subglobu- 
lar smooth nucleus and five subsequent whorls; spiral sculpture of five 
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