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154 American Seashells
Cerithium muscarum Say Fly-specked Cerith
South half of Florida and the West Indies.
Plate 19m
I inch in length, moderately elongate. Siphonal canal rather long and
twisted to the left. 9 to 1 1 nodulated axial ribs on each whorl. Base of shell
with a very strong spiral cord, often nodulated. Former varices rarely pres-
ent. Apertural side of body whorl convex. Color slate- to brown-gray,
usually with brown to reddish specks in spiral rows. Common in shallow,
warm waters on the west coast of Florida.
Cerithium literatiim Born Stocky Cerith
Southeast Florida, Bermuda and the West Indies.
Plate 19I
I inch in length, half as wide; siphonal canal short. Aperture side of
body whorl slightly flattened. Usually i weak, former varix present. With
numerous coarse spiral threads, and with a spiral row of 9 to 12 sharp, promi-
nent nodules just below the suture. Sometimes a second, smaller row of
spines is on the periphery. Color whitish with spiral rows of many black
or reddish squares. Common in shallow water on the Lower Florida Keys.
Cerithium ebiirneum Bruguiere Ivory Cerith
Southeast Florida, the Bahamas and Greater Antilles.
Plate i9q
% to I (rarely iK>) inches in length, variable in shape, but usually
moderately elongate. Each whorl has 4 to 6 spiral rows of from 1 8 to 2 2 small
rounded beads. The beads are slightly larger in the middle row. There are
usually a number of fairly large, former varices. Color variable: all white or
cream, or with reddish brown blotches. Very common in shallow water.
C. versicolor C. B. Adams is this species. Compare with algicola which may
ultimately prove to be a genetic form of this species.
Cerithiwn algicola C. B. Adams Middle-spined Cerith
Southern third of Florida and the West Indies.
Plate I9P
I inch in length, similar to eburneum, but characterized by each whorl
having the middle spiral row of 9 to 12 beads fairly large and pointed. These
large beads may be axially drawn out to form low ribs. Former varices are
not often present. Color as in ehumewn. Common in the West Indies. C.
literatum has its strongest row of spine-like beads just below the suture.
Certthiu7n variabile C. B. Adams Dwarf Cerith
South half of Florida to Texas and the West Indies.
Plate 19-0