MANUAL OF THE MOLLUSCA. 



apox of embryonic shell slightly twisted ; crown never pro- 

 minent, incurved, and nearly terminal, usually thin, with an 

 opalescent hue. 



Animal. Mantle fringed at its edges with cirri j gills not so 

 numerous as in FateUa, and forming a shorter plume, which ia 

 interrupted over the head. 



Hehion lives on Laminarice and sea- weeds of a similar kind, 

 and is therefore sublittoral. 



Distribution. Species few, but having an extensive range. 

 Europe, West and South Africa, Cape Horn, and Australia. 



Fossil, included in Patella. 



Lepeta, Gray (p. 281). 



Derivation, possibly from lepas, the ancient name of the 

 limpet. 



Type, Patella caeca, Miiller. 



Shell minute, apex posterior. Animal blind. 



PnoprLiDiUM, Forbes and Hanley (p. 281). 



Derivation, from its affinity to the genus Pilidium. 



Type, P. ancyloide, Forbes. 



Shell similar to Lepeta, but differing in always having a dis- 

 tinctly spiral apex and a plate or septum inside the cro-^Ti. 



Animal blind, as Tedura. fulva and Lepeta cceca of this family. 



' ' The tongue is very long, and the brown central spines con- 

 Bpicuous under the microscope resemble bramble-thorns in 

 miniature." — (Forbes and Hanley.) 



Distribution, 1 species. Shores of Ireland, Scotland, Sweden. 



GaddsTA (p. 281). 



Sub-genus: — Eoivellia, Cooper. Animal with broad flat ten- 

 tacles, rounded and pectinated in front, projecting beyond the 

 shell ; foot moderate, round. Shell as in Gadinia. 



Family XIV. — Dentallad^. 

 Gadtjs, Eang, 1829. 



Synonym, Helonyx, Stimpson, 1865. 

 Example, Dentalium clavatum, Gould. 



Shell small, resembling that of Dentalium, contracted at the 

 anterior extremity, polished. 



Anim/xl with a greatly elongated cylindrical foot, obtuse at 

 40 



