Page:American Seashells (1954).djvu/242

192 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. Super jamily TONNAGE A 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 Plate 25s Southeast Florida and the West Indies. % 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 geno- type, 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 Plate 96 North Carolina to the Gulf of Mexico and the West Indies.