TUBE OP PANTHALIS. 185 



proboscis simultaneously appears resting in a fold on the 

 upper surface of this lower part. This tentacle doubtless 

 ascertains whether food is within striking distance in which 

 event the second portion of the proboscis is brought into 

 action, seizing its prey by means of the four savage-looking 

 fangs, assisted by the smaller teeth with which the animal 

 is endowed. 



The campanulate structure of the elytra is interesting, 

 and raises questions in my mind as to how far these are 

 organs of respiration specially adapted to expose as large 

 a surface as possible to the action of the water, in view of 

 the confinement in which Panthalis usually lives. 



From specimens which I have had under observation 

 during several months I should gather that, although 

 Panthalis does occasionally desert its tube and make new 

 ones, as suggested by Prof. Herdman, (see British Asso- 

 ciation Report, Oxford, 1894) this is not a very frequent 

 occurrence, and that when once the worm is well-settled its 

 general habit is to rest with its head at the mouth of its 

 tube watching for its victims, an opinion apparently 

 supported by the facts that two tubes dredged in September 

 last, have each one end hard and leathery, as though it 

 had been long buried and hardened by absorption of 

 excreta or other matter, and that the complete formation 

 of such tubes seems to be a work of time. The animal 

 appears always to leave its tube when about to die, which 

 will account for many empty ones being brought up in 

 the dredge. 



As to its mode of locomotion, Panthalis usually walks 

 or creeps upon the mud. I have only once seen it swim, 

 which it did in a clumsy way, by moving its elytra and 

 body on an occasion when the water had become foul and 

 unbearable. 

 Throughout this paper, I have, for the sake of con- 



