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192 Avierican Seashells
smaller shell. Nucleus of operculum often stained with brown. Color white,
but often with weak, light-brown color markings. Commonly dredged in
shallow water to 1 8 fathoms.
Superjamily TONNAGEA
Family CASSIDIDAE
Genus Sconsia Gray 1847
Sconsia striata Lamarck Royal Bonnet
Southeast Florida to off Texas and the West Indies.
Plate 9h
1/4 to 2% inches in height. Shell hard, polished, often with numerous
fine, spiral incised lines. Usually two old varices are present. Rare, but re-
cently being brought in by shrimp trawlers in the Gulf of Mexico. A choice
deep-water species.
Genus Morum Roding 1798
Moru77t oniscus Linne Atlantic Wood-louse
Southeast Florida and the West Indies.
Plate 25s
% to I inch in height. Whorls with 3 spiral rows of rather prominent
bulbous low tubercles. Parietal wall glazed over and ingrained with numer-
ous white dots which are developed into minutely raised pustules. Color
(with thin, velvety, gray periostracum removed) whitish with specklings or
mottlings of brown or black-brown. Nucleus papilliform, white or pink.
Operculum very small, corneous, and with its nucleus on the side. Nocturnal.
Just below low-tide mark under coral slabs.
Genus Vhaliwn Link 1807
These are miniature helmet shells which rarely exceed a length of 5
inches. The Scotch Bonnet of Florida (Phaliiim grajiulatwn) is well-known
to most collectors. This genus differs from Cassis in having much smaller
shells which do not have an extended, upturned siphonal canal and do not
develop a massive parietal shield. Typical Fhalium which has 4 or 5 tiny
spines on the base of the outer lip (as for example in the Indo-Pacific genotype,
P. glaiicwn Linne) is not represented in American waters. Our two
species belong to the subgenus Seinicassis which lacks these tiny spines.
Operculum as in Cassis.
Subgenus Semicassis Morch 1852
Fhalium granulatum Born Scotch Bonnet
North Carolina to the Gulf of Mexico and the West Indies.
Plate 96