A SEASIDE RAMBLE 215 



radiating from a kind of ring in the centre of the 

 stone. This cannot be an accident, for much the 

 same characters are to be observed in each of the 

 three other specimens. Now these are well worth 

 the expense of polishing. Few objects are more 

 fascinating to the collector. They are choanites, so 

 called by Dr. Mantell. But this name simply means 

 a hollow or funnel-shaped body, and conveys but 

 little to our minds. These were sponges, somewhat 

 pear-shaped, which lived on ocean floors long before 

 man came upon this earth. There must have been 

 an abundance of these sponges, for choanites can be 

 found on most pebbly beaches of the South of 

 England. It is doubtful whether similar sponges 

 live now. Those ancient ocean floors have been 

 gradually raised up, so as to form the cliffs and beds 

 of rocks now being worn down by sea action and the 

 weather. 



Examine the stones carefully. The tubes so 

 characteristic of the choanite must not be mistaken 

 for feelers. Every sponge has one or more large 

 openings, or oscula, out through which the used-up 

 water flows, while it also possesses quite a multitude 

 of small canals, through which the fresh sea water 

 is conveyed to every part of the sponge structure. 

 The markings which we see on the polished choanite, 

 and which resemble feelers, are these smaller canals 

 which were originally embedded in the jelly- flesh 

 structure known as sarcode. 



In the course of the gradual replacement of the 



