288 



POLYCHAETA 



< 1 1 , 



their tenements, and these observations, though made nearly half 

 a century ago, have required very little addition or correction in 

 modern times. In speaking of Sabella, he writes as follows : 



Fig. 153. 



Fig. 152. The tube of Pectinaria auricoma. x 3. 

 (From M'lntosh.) This is its natural position as 

 carried about by the animal. 



Fig. 152. 



Fig. 153. The upper end of the tube of Terebella con- 

 chilega. Slightly enlarged. (From M'lntosh.) 



" Let a tall and ample crystal jar containing a Sabella be 

 emptied of its contents and speedily replenished with sea-water ; 

 the animal, if in view, has retreated during the 



the orifice of the tube is closed, all is at rest. 



short interval ; 

 But soon after 



