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CERITHIIDAE 15 3
2 yellowish white, swollen varices on the spire. A very common species
found in large colonies on mud flats.
Cerilhidea Balillar'ia Cerilhium
Figure 39. Last whorl and opercula in the Horn Shells. (From J. Bequaert in
Johusoina.)
Subfamily BATILLARIINAE
Genus Batillaria Benson 1842
Cerithium-like in appearance. Siphonal canal very short and twisted to
the left. Outer lip smooth inside. Operculum round, multispiral and horny,
while in Cerithidea and Cerithium it is paucispiral.
Batillaria mi7iima Gmelin
South half of Florida and the West Indies.
False Cerith
Plate 19s
V2 to % inch in length, resembling the Dwarf Cerith, C. variabile (see
below). Color varies from black, gray to whitish, and often has black or
white spiral lines. Finely nodulose with coarse axial swellings and uneven
spiral threads. The siphonal canal is very short and twisted slightly to the
left. Operculum multispiral. A very common intertidal species. Percy
Morris (i95i» pl- 31^ %• 15) labels this species as Cerithidea turrita.
Family CERITHIIDAE
Genus Cerithium Bruguiere 1789
Thericium Monterosato is this genus. The operculum is horny, thin,
brown and paucispiral. Most species in the genus are shallow-water dwellers.
Cerithium floridanum Morch
North Carolina to the south half of Florida.
Florida Cerith
Plate 1911
I to 1V2 inches in length, elongate. Spire pointed, with 2 or 3 white,
former varices on each whorl. Siphonal canal well-developed. With several
spiral rows of 18 to 20 neat beads per whorl between which are fine, granu-
lated spiral threads. Color whitish with mottlings and specklings of reddish
brown. Distinguished from C. literatimi by its more elongate shape and
neater, smaller, more numerous beads. Common in shallow water.