250 Descriptive Catalogue of the British Testacea. 
parts of their structure. The coverings of the Sabelle seem 
to be more of an adventitious nature, and may be considered 
rather as serving the purposes of habitations, than as being 
organized integrals of the contained animal.—If these ideas 
be correct, the genus Sabella does not come within our pro- 
vincei 
CHI Sese 
