TUBE OF PANTHALIS. 337 



repair the damage, lying on its back, and thus affording 

 me a splendid view of its operation through the open top 

 of the tank. Thus seen, the mouth of the new tube had 

 the appearance of a minute crater about j an inch external 

 diameter with walls barely yV' thick at the edge. With 

 its head very slightly projecting through the opening, and 

 the two long palps bent over the edge ventrally, Panthalis 

 began moving the second pair of parapodia in a manner 

 quite different from the ordinary rowing or walking action 

 of such limbs ; the motion, instead of being longitudinally, 

 was transversely to the body, i.e., the extremities of the 

 right and left pairs of parapodia w^ere brought together so 

 as almost to meet in the central line of the underside of 

 the body. 



At intervals of two or three seconds, the animal, for 

 several minutes at a time, continued thus to bring together 

 and to separate these limbs ; the tips of the buccal tenta- 

 cles or bristles, too, at short intervals were brought together 

 and applied first to one point and then to another of the 

 tube, as though grasping and removing something from 

 place to place ; and although no threads could with 

 certainty be seen (though I thought I saw the haziness of 

 a cobweb) I had not the slightest doubt that Panthalis 

 was thus weaving its tube ; combing and weaving the 

 threads by means of the setae contained in these parapodia, 

 and arranging them with the buccal tentacles, an opinion 

 which I have since confirmed with another specimen, 

 when I saw the threads actually carried, as described 

 above. The process was repeated at different levels in 

 the tube which would account for the layers originally 

 noticed in the tube structures. Now and again the elytra 

 took part in the formation of the tube, and by rising and 

 falling were used to expand its mouth, whilst occasionally 

 the edge was drawn in upon the animal and then forced 



