MOLLUSC A. 



215 



Integro-pallialia {Integri pallia), with short siphons, 

 and even pallial line ; and the Sinupallialia, in which 

 the siphons are long and retractile, and the pallial 

 line bears a deep indentation corresponding with 



Fijr. '67. — Shells of Slphoniate MollnscB. 

 a, PJiolas dactylus. h, A Razor-shell, Solen 



their site. One of the most carious of these is. the 

 Fholas dactylus, which bores itself a burrow in soft 

 rocks by using the edge of the shell, assisted by 



