CIRRATULUS BOREALIS. 327 



CHAPTER XXXIII. 



CIRRATULUS BOREALIS "THE NORTHERN CIRRATULUS." 



THE length of this beautiful Annelide (PL VI. fig. 4) 

 is about four inches ; its body is composed of numerous 

 segments tapering towards each extremity; but the 

 most striking feature whereby it is distinguished con- 

 sists in the possession of numerous long and flexible 

 cirrhi, or thread-like appendages, made up of an in- 

 finite number of rings attached along the entire 

 length of its body. 



These cirrhi, apparently 



" More soft and sensible 

 Than are the tender horns of cockled snails," 



arise on each side from every alternate segment of the 

 body, and besides being instruments of prehension, 

 apparently perform the functions of the branchiae or 

 breathing organs of other Annelidans. They run in 

 two rows down the back, and are continued nearly to 

 the posterior extremity; they are longest, however, 

 in the vicinity of the head, becoming gradually shorter 

 as they recede backwards. When the animal crawls, 

 these cirrhi lie along the back, presenting a very 

 singular appearance. 



The colour of the Cirratulus is generally red, some- 



