58 POPULAR HISTORY OF THE AQUAFtIU:\r. 



circle of bent cane or wire, it would give tlie idea of 

 the door or valve we are describing, only on a very large 

 scale ; the bladder answering to the almost impalpable 

 membrane, and the circular frame answering to the horny 

 rim of the door. Sometimes, however, patient observers 

 have seen the polype retreated far within his cell, and 

 still holding the door wide open, so as to permit the free 

 circulation and inhibition of the watery element, but with 

 the spring ready to be drawn back on the approach of 

 danger. The Anguinaria spatidata is found not uncom- 

 monly twining like a ^^ gentle evergreen,^^ about small sea- 

 weeds at low water, near the Devonshire coasts. 



Cellularia ciliata. 



The Ciliated Cellularia is parasitic in its habits, like the 

 Angui7iaria. There is a kind of tubercle on the outside 

 of the cell, which is open at one end, with a movable 

 valve, presenting an appearance in form resembling that 

 of a flower of Calceola. It has also been compared to 

 the head of a bird, the valve answering for the lower 

 mandible of the beak. This valve opens and shuts with 

 a sudden, snapping motion; and the edges of the upper 

 and lower mandibles are both armed with tooth-Hke points. 



