8 



MARINE ANIMALS OF MASSACHUSETTS BAY. 



of expansion and contraction. Fig. 2 represents it with all its 

 external appendages folded in, and the whole body flattened ; in 

 Fig. 3, the tentacles begin to steal out, and the body rises slightly ; 

 in Fig. 4, the body has nearly gained its full height, and the ten- 



rig. 3. 



tacles, though by no means fully spread, yet form a delicate 

 wreath around the mouth ; while in Fig. 5, drawn in life size, the 



Fig. 5. 



Figs. 2, 3, 4. Actinia in different degrees of expansion. (Ayassiz.) 



fig. 5. The same Actinia (Metridium marginatum) fully expanded; natural size. 



