CHAPTEE V. 



THE POLYPS AND COKAL-MAKERS. 



The polyps are represented by the common Actinia of 

 our coast (Meiridimn marginatum. Fig. 30), which is to be 

 found between tide-marks on rocks under sea-weeds, or in 



Fig. 30. — Common Sea-anemone. Natural size, with the tentacles expanded. 



tidal pools, but grows most luxuriantly on the piles of 

 bridges. It readily lives in aquaria, where its habits may 

 be studied. An aquarium may be ir^provised by using a 

 preserye-j'ar or glass ^Igbe^ eovering the bottom with sand. 



