HABITS OF THE ONTPHIDJE. 305 



111 my aquaria, these worms were by no means thus 

 sedentary ; on the contrary, when not alarmed, they were 

 very active, and travelled about freely, carrying their 

 tubes with them, the movement of which was effected by 

 protruding half an inch or more of the anterior portion 

 of the body from the front end of the tube, and by 

 muscular effort jerking the tube, or dragging it, with a 

 caterpillar-like action, into new positions. 



The distinctly curved form of the forceps-like bristles 

 of the first parapodia gives the worm, when travelling 

 about, a firm foot-hold on the sea-bottom, and is doubtless 

 connected with this habit, as is possibly also the bract 

 on the fore feet. During movement the hold on the tube 

 itself is doubtless retained by the stout forcipate bristles 

 of the other parapodia. 



To keep these worms alive in captivity, I found it 

 necessary to cover the floor of the aquarium with muddy 

 sand and shells obtained, by means of a bucket dredge, 

 from the sea-bottom upon which the animals were 

 captured. Under these conditions they lived for several 

 months, subsisting upon the food obtained from the mud, 

 their habits in this respect evidently being less carni- 

 vorous than Johnson supposed. 



Only when alarmed, as for instance, when rocked about 

 by movement of the aquarium, or by some unusual circum- 

 stance (such as my subsequent experiments), did they 

 show any desire to embed themselves ; but on such 

 occasions Hyalincecia will protrude the fore part of its 

 body through the small end of the tube, and quickly 

 burrow partially under the surface, dragging its tube 

 with it. 



The tube of Hyalinoecia tubieola, as is well known, is a 

 transparent, chitinous, quill-like structure, from 2 to 4 

 inches in length, slightly curved and tapering, as shown 



