98 Marine Shells of the Western Coast of Florida 



Family DENTALllDAE 



The mollusks of this family live partly buried in the sand or 

 ooze of the sea bottom. They assume a position oblique to the 

 surface with the siphon end of the shell projecting in order to pro- 

 vide for free circulation of the currents of sea water necessary to 

 the creature's existence. From the larger, buried end of the shells, 

 the animal extrudes the foot and numerous long, delicate filaments, 

 club-shaped at their tips. These filaments feel about in the sand and 

 capture small prey, usually Foraminifera, but sometimes small 

 bivalves, which are carried to the mouth parts. 



This family has but one genus, Dentalium; all its species have 

 elongate, tapering, tubular shells, more or less curved in the long 

 axis; they are open at both ends and diminish regularly in diameter 

 from the large anterior opening to the small posterior orifice. The 

 anterior opening is simple, sharp-edged, never contracted nor re- 

 flected. The posterior end of the shell is truncated, and its opening 

 may be simple, notched, or slit and sometimes furnished with a 

 small supplementary tube extended from the orifice in the direction 

 of the long axis of the shell. The dorsal aspect of the shell is concave. 



Most of the Dentalia are white, a few are tinted with pale 

 salmon-pink or a green tone near the apex, but any coloration soon 

 fades after the death of the animal. The quality of the shell varies 

 from a dull, chalky surface to a high polish. Apical characters, 

 sculpture, and the degree of curvature of the shell are important 

 features in the determination of species. 



Genus DEXTALIFM Linne, 1758 



Dentoliuinis' laqiieatum Verrill PL 20. fig. 128 



Alt., to 45; diam., 3.5 to 6 mm. Anterior part of shell only 

 slightly arched, tip sharply curved; aperture circular and fluted; 

 opaque-white; apex is angled by 9 to 12 strong ribs with equal- 

 sized, concave intercostal spaces. The ribs become broader and inter- 

 spaces less concave toward the anterior extremity; fine longitudinal 

 lines on the ribs of unworn shells and almost microscopic reticulation 



169 Lat., dens, dcntis, tooth; laqueo, to adorn with panelled surface. 



