TEEEBELLA CONCHILEGA. 301 



day, as if night were approaching. If supplied with 

 different-coloured fragments of shell, a variegated 

 tube in bands, or otherwise constructed, may be 

 obtained. A beautiful edifice is composed of the 

 shivered pearly internal strata of oyster-shells : and a 

 specimen having been dislodged from its tube, and 

 committed to a vessel containing a few shelly frag- 

 ments, some sand, and a number of small Venetian 

 beads, has been known to employ them all indiscri- 

 minately in the fabrication of a new dwelling. In 

 default of comminuted shell, the Terebella conchilega 

 will build a tube exclusively of sand. 



By eliciting the propensities of this animal, the 

 observer may have much agreeable and interesting 

 entertainment. 



If dislodged from its tube, and placed in a vessel of 

 sea- water, the Terebella profits by the earliest pro- 

 vision of fresh materials to construct another. While 

 this is conducted up the side of the vessel, the tenta- 

 cula, those essential mechanical auxiliaries, are busily 

 employed. A silky tentaculum seizes a fragment to 

 be elevated to the orifice; it is too ponderous and 

 unwieldy, and two or three other tentacula then unite 

 their efforts in raising the load to its intended posi- 

 tion. An empty mussel-shell, about half an inch 

 long, was thus elevated and secured in its place, to 

 augment an edifice in progress. 



Great expedition is exhibited in fabricating a tube 

 solely of sand, under a total deficiency of more fa- 

 vourite materials, and heavy loads of it are dragged 

 towards its naked body, with which the mouth is 

 speedily occupied; but shell is best adapted to the 



