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CERITHIIDAE 155
% to /4 inch in length, not elongate. Apertural side of body whorl
sometimes flat, i to 2 former varices on last whorl. 3 or 4 spiral rows of
even-sized fine beads on the whorls of the spire. Color dark brown-black,
but sometimes whitish with heavy specklings and mottlings and bands of
reddish brown. Very common under rocks in warm water. Do not confuse
with Batillaria ininwia (see above).
Genus Bittium Gray 1847
Shell small, very slender, spire high and body whorl small. Whorls
varicose. Nucleus of about 3 glassy, smooth whorls. Aperture ovate, the
anterior canal broad and stout.
Subgenus Bittiwn s. str.
Bittiu?7i altematiim Say Alternate Bittium
Gulf of St. Lawrence to Virginia.
Adults very small, % to /4 inch in length, light- to dark-brown in color,
sometimes translucent or with specklings. Suture impressed, whorls rounded.
Sculpture on top whorls either cancellate or with 4 to 5 spiral rows of beads,
or occasionally with axial, nodulated ribs. Base with small spiral cords. Outer
lip flaring, thin and sharp. Columella short, twisted at the base and stained
brown. Very abundant from tidal flats to 20 fathoms.
B. virginicuffi Henderson and Bartsch from Chincoteague, Virginia, is
similar, but very elongate, more whorls, with a much more flaring and basally
projecting lip, and with a large, whitish, former varix on the body whorl.
Bittium variimt Pfeiffer Variable Bittium
Maryland to Florida, Texas and Mexico.
Plate 191
Adults similar to altematiim, but smaller (% inch), nearly always with
a former, thickened varix. The aperture is proportionately smaller and the
base of the apertural lip is squarish instead of rounded. The last third of the
body whorl is generally destitute of sculpturing. Common in eel-grass just
below low tide.
Subgenus Stylidium Dall 1907
Bittium eschrichti Middendorf Giant Pacific Coast Bittium
Alaska to Crescent City, California.