TUBE OF PANTHALIS. 331 



desire, and was in fact the exact state of affairs I was 

 aiming to produce, but had not hoped to attain so easily. 

 This habit of annehds in captivity burrowing or building 

 against the glass, has often been helpful to me. It affords 

 excellent opportunities for studying the form and habits of 

 the animals under natural conditions, the interior of the 

 channel being exposed to view. By carefully changing 

 the water (by syphoning) the worm was soon made to 

 feel at home, and except for the occasional vibrations to 

 which it was always most sensitive, seemed to be unaware 

 of the shallowness of the water to which it had been 

 transferred. At first Panthalis was somewhat cautious 

 about exposing itself in the clear channel, and the only 

 parts visible were the head, and two long palps ; between 

 which, two red spots were seen, and on either side the 

 cirri of the first pair of parapodia. These were seen 

 peeping out into the new channel, the remainder of the 

 body of the worm being hidden in the old tube, or under 

 the mud which had been placed on the floor of the tank. 



Gradually the animal gained confidence, and during 

 the day an inch of its length was exposed to view, and by 

 night almost the full length of its body was reposing 

 quietly in the new channel, the posterior extremity only 

 remaining buried in the old tube. Upon examination by 

 lamp-light, I found that the glass, just at the commence- 

 ment of the clear burrow, was for a very short distance 

 covered w4th mucus-like threads forming a " cobweb." 

 The animal itself was at first very sensitive to the artificial 

 light, but subsequently bore it better, though it evidently 

 felt the heat, as it contracted the portion of the body on 

 which the light w^as concentrated. As seen in its burrow, 

 the animal possessed 60 pairs of parapodia, and was about 

 3^- inches long, (the tube in which it was captured being 

 about half an inch longer). The width, across the 



