48 A MANUAL 



mone never approaches the size of the largest 

 " strawberry." Now if one w^ere a variety of the 

 other, and both were living in like situations and 

 fed in the same manner, it is at least probable that 

 there would be no permanent difference in the point 

 of size. 



In our pan No. 2 we must remember that all our 

 specimens are studded throughout the whole surface 

 of their bodies (though more scantily towards the 

 base) with large, conical, coloured, perforated tuber- 

 cles or warts. We take up one of these animals, and 

 ask, Are its warts arranged in vertical lines, and do 

 six or more of these lines contain larger and wdiiter 

 warts than the rest ? If so, we may be tolerably 

 sure that we have the beautiful Actinia gemmacea, 

 "the gem." When closed its body resembles in 

 shape an oval waistcoat-button. When open it dis- 

 closes about fifty tentacles, long, large, of an olive - 

 colour, barred on the side next the mouth by streaks 

 of white. The colours of the oral disc are com- 

 monly gray on the outside, then yellow, and next 

 bright green, which tint surrounds the mouth. The 

 shape of the body when expanded is very variable, 

 generally it is columnar, and frequently it rises in 

 this shape to the height of one or more inches. The 

 average diameter of its body, when in contraction, is 

 half an inch. 



Next, we will look in the same pan for a specimen 

 whose warts are not arranged in regular vertical 



