ANALYSIS OF THE GENERA. 
Tentacles moderately long, slender. 
Disk perfectly retractile. 
Column destitute of suckers 
Column fumished with suckers 
Column clothed with a rough ei^idermis . . . 
Disk imperfectly retractile. 
Base annular ; parasitic on shells 
Base entire ; not parasitic 
Tentacles mere warts ; set m radiating bands {Not 
British) ... 
Actinolola. 
Sagartia. 
Phellia. 
Adamsia. 
Gregoria. 
Biscosoma. 
