MANUAL OF NATURAL HISTOEY. 131 



25. Family. — Wing-Shells (Strombidse). Eyes on 



the end of cylindric peduncles, with the ten- 

 tacles on their middle ; mantle with outer 

 margin lobed ; foot divided, formed for leap- 

 ing not walking ; operculum claw-like ; shell 

 with the outer lip expanded, notched near 

 the fore part, changing in form with age. 

 Marine. 



26. Family. — Auger-Shells (Terebellidae). Eyes on 



the end of cylindric peduncles ; tentacles 

 none ; foot compressed, sub-ovate ; operculum 

 horny, tricuspid externally; shell subulate, 

 involute ; aperture linear, outer lip simple. 

 Marine. 



27. Family. — Cones (Conidse). Eyes near the ends 



of the tentacles ; teeth barbed, in two rows ; 

 mantle enclosed ; operculum ovate, nucleus 

 apical ; shell cone-shaped ; aperture straight ; 

 outer lip simple. 



28. Family. — False Wing-Shells (Aporrhaidae). Eyes 



sessile on outer bases of tentacles; mantle with 

 the outer edge expanded or lobed ; siphon 

 bent to the right ; foot simple ; operculum 

 annular, ovate ; shell with the outer lip sinu- 

 ous, lobed, or digitate. 



29. Family. — Lattice- Shells (Cancellariidse). No 



tongue nor teeth ; eyes sessile on outer bases 

 of tentacles ; mantle enclosed , siphon ru- 

 dimentary ; operculum none ; shell spiral, 

 whorls cancellated ; columella with plaits. 

 Marine. 



