II A BITS OF THE ONUPHIDJE. 315 



valves were exposed, the pockets being one-quarter of an 

 inch deep, and one in advance of another, as shown, 

 v, v, fig. (S. Probably this was the posterior end of a tube. 



From the foregoing examples, it appears that this 

 interesting" method of defence obtains throughout the 

 family. Whether it is confined to the Onuphidse, or not, 

 I cannot say, but personally I am not aware of any other 

 instance. Possibly careful search might prove its 

 existence in some species of Eunice, or in other 

 unsuspected quarters. 



What may be the habits of these worms inhabiting the 

 deepest part of the ocean can only be conjectured ; but 

 judging from the formation of the foot-bristles (as figured 

 by Mcintosh in the "Challenger" Report), from the 

 internal structure of the tube, and from the fact that one 

 side of the tube is usually smooth, it seems probable that 

 they, like our British forms, may be wanderers. This 

 view cannot, however, be taken without exception, and I 

 freely admit that the case of Nothria willemoesii, from 

 Japan, with its hooked and spine-covered tube, is one 

 which presents very great difficulties. 



It is hard to suppose that this tube (a masterpiece of 

 constructive skill) was ever dragged about the sea-bottom, 

 powerful though its tenant evidently was. Moreover, 

 about one-third (1J inch) of the tube at one extremity is 

 somewhat flexible, and perfectly free from the long 

 slender spines with which the remaining two-thirds is 

 beset (as regards two-thirds of its circumference), suggest- 

 ing the possibility that this extremity may have been 

 embedded in the muddy bottom. 



By the kindness of Prof. Bell, I some years ago 

 examined these tubes at the British Museum, and made a 

 rough sketch (fig. 9) of the specimen above referred to. 



The tube is about £ inch in internal and f inch external 



