Cassididae and Tonnidae 149 



ferred by all species of the Cassididae, where many bivalves fall 

 victim to their predatory habits and voracious appetites. 



The animals possess eyes, formidable jaws, a radula and a 

 voluminous foot which participates in the secretion of the shell. 



Typical shell is ventricose and solid, with a large inflated body 

 whorl and a short, but well-elevated spire. The aperture extends the 

 length of the body whorl and is prolonged into a short, sinistrally 

 curved canal. The outer lip is thick, often reflected, and usually 

 dentate within. The columella is plicate or granulose. 



Genus PHALIUM^es Link, 1807 



Subgenus SEMICASSIS Morch, 1852 



Phaliuin gTanulatum-''» (Born) {S. gibbus Gmelin) PI. 29, fig. 208 



Oval shell with rather acuminate spire, shell pink to nearly white, 

 with six series of squarish cinnamon spots, those at suture and extreme 

 base often smaller, irregular or weak. Deeply grooved spirally, the mod- 

 erately convex or sometimes nearly flat raised coi'ds being much wider 

 than the grooves, seventeen to nineteen on last whorl, second from suture 

 generally narrow. Upper four or five cords generally crossed by narrow 

 tubercles, these may be weak or practically absent. A few have a varix 

 preceding that at the lip by about a whorl, moi-e or less. Large speci- 

 mens from 75 to 80 millimeters long.-'" 



Operculum pale brown, semilunar with plications radiating from 

 nucleus near inner border to the finely dentate outer border. 



One fresh juvenile shell of Cassis madagascarensis has been 

 dredged in four fathoms off Sanibel Island. 



Family TOlVNIDAE'-^^i 



A family of mollusks with close affinities to the Cassididae, also 

 distributed m warm seas and preferrmg sandy bottoms. 



The animals are notable for the extreme length of the siphon, 

 the large foot, and the reputed ability to secrete sulphuric acid. 



Genus FICUS Roding, 1798 

 Ficus communis-"- Roding (F. papyratia Say) PI. 29, fig. 209 



Alt., 90 mm. Shell thin, translucent, pear-shaped, brownish or 

 bluish gray; thin periostracum, spire short, depressed, top of shell 



-®* Gr., phalios, for phalaros, with white patches. 



269 Lat., cassis, helmet; granulatum, granulated; gibbus, a hump. 



27opilsbry, H. A., and McGinty, T. L.: Nautilus, vol. 52, No. 3. Condensed 



description. 

 -^^ Lat., tonna, a cask. 

 -^- Lat., communus, common; ficus, fig; papyraceous, made of paper. 



