98 THE ELEMENTS 



sable parts of their structure. The 

 coverings of the Sabella seem to be 

 more of an adventitious nature, and 

 may be considered rather as serving 

 the purposes, than as being organized 

 integrals of the contained animal. — 

 If these ideas be correct, the genus 

 Sabella does not come within our 

 province/* 



In Turton's Linne 25 species of 

 Sabelise are described ; and Mr. Mon- 

 tagu has discovered 12 on the British 

 coasts. 



SPECIFIC DESCRIPTION 



OF THIS 



PLATES. 

 PLATE I. 



MTJLTIYALYE SHELLS. 



Fig. lst.—LEPAS RUGOSA — 



With a sub-cylindric shell, usually 



