SERPULA. 



Serpula, Spirorbis^ Vermilia et Vermetus^ Lam. 



TESTA tubulosa, cylindracea, posticfe attenuata; 

 vel in spiram productam seu orbicularem, dis- 

 coideam, convoluta vel irregularis; interdum 

 inferna superfieie planulata omnino fixa, inter- 

 dum repens, spira non distineta; interdum par- 

 tim erecto-undata, varie contortuplieata; rar5 

 admodum poene libera: aperturd plerumque 

 rotunda, margine vel simplici, vel dentibus seu 

 angulis varie armato. Operculum testaceum 

 vel corneum, orbiculare, forma pervariabili. 



The differences which have induced Lamarck to separate 

 the Genera Spirorbis and Vermilia from Serpula depending 

 upon circumstances altogether variable, cannot be con- 

 sidered as sufficient reasons for removing from that Genus 

 the little testaceous coverings of these Annelides: but the 

 circumstances on account of which he has removed Ver- 

 metus, not only from Serpula but from the family itself, 

 require a more critical examination, inasmuch as these 

 reasons have induced him to arrange it with his Scalariens, 

 Let it be observed that Adanson, from whom Lamarck 

 adopted his Vermetus, has included with it several others 

 that evidently belong to Lamarck's Serpula, only describ- 

 ing the animal of one : it will next be seen that in many 

 of its most important characters the animal so described 

 ,by Adanson accords exactly with that of Serpula: and 

 then that both his description and figure are in other 



