i66 C O N C H O L O G Y. 



1 have given a full account of the fectlons, 

 and the fpecles that rank under them, in 

 my twenty-fifth ledure on foffils ; which 

 I fhall here briefly recapitulate. 



Section I. Ammonia, whofe backs are 

 quite fmooth and plain : Amnxonia dorfo 

 Ic^vi. 



Section II. Ammonia, whofe backs are 

 ftriateu, fulcated, or ribbed : Ammonia 

 dorfo ftriato, fulcato, vel coftato. 



Sefbion III, Ammonia that have a plain 

 prominent ridge along the back : Ammo-^ 

 lua limbo prominulo per totum dorfum 

 duclo. 



Section IV. Ammonia with a plain pro- 

 minent ridge between two furrows : Am- 

 monia limbo prominulo inter duo sfulcos 



Seclion 



