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TROCHIDAE 113
CalHostoma jujubinuni Gmelin Jubjube Top-shell
Lower Florida Keys, the Bahamas and the West Indies.
Plate 3p
% to I /4 inches in length. Characterized by the deep, narrow, smooth-
sided umbilicus which is bordered by a spiral, beaded thread, and by the
swollen, rounded periphery of each whorl, which in the spire is located just
above the suture. Color ranges from brownish cream to reddish and is often
maculated with white splotches near the periphery. Typical jujubinum has
a spire angle of about 50 degrees; the spiral threads on the whorls are weakly
beaded, and the umbilicus is almost closed.
C. jiijiibimim tampaeiise Conrad (North Carolina to both sides of Flor-
ida to Yucatan) varies in spire angle from 50 to 65 degrees, is not always so
swollen at its periphery, and has 9 to 10 well-beaded spiral threads between
each suture.
CalHostoma occidentale Mighels and Adams North Atlantic Top-shell
Nova Scotia to Cape Cod, Massachusetts. Europe.
^ inch in length, equally wide. Whorls convex and with 3 to 4 strong
spiral cords, the 2 lower ones smooth, the upper one beaded. Color pearly-
white. No umbilicus. Outer lip fragile. Moderately common from 10 to
365 fathoms.
CalHostoma bairdi Verrill and Smith Baird's Top-shell
Plate 3—0
Massachusetts to North Carolina (and to Florida).
1 to iVi inches in length, about as wide. Angle of spire about 70 degrees.
Sides of spire straight to slightly convex. Base rather flat. Periphery angular.
Sculpture of 6 to 7 spiral rows of small, neat beads, with those on the top-
most row being the largest. Suture difficult to find. No umbilicus. Color
brownish cream with faint maculations of light reddish. Not uncommon
from 43 to 250 fathoms.
C. bairdi psyche Dall (North Carolina to Key West, 30 to 130 fathoms)
is usually % inch in length, slightly wider, with a spire angle of about 75 to
80 degrees, and the color is lighter and more pearly. Base with 3 or 4 spiral
brown lines. It has a chink-like depression beside the umbilicus. Uncommon.
C. subumbilicatum Dall is a form of this species whose umbilicus is half open.
CalHostoma tricolor Gabb Three-colored Top-shell
Moss Beach, California, to Cape San Lucas, Mexico.
Figure 330