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. 



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. 



