68 



MARINE ANIMALS OF MASSACHUSETTS BAY. 



heads. This protecting calycle is wanting round the heads 

 of the Tubularians, though their stems are surrounded by a 

 sheath. 



Sarsia. (Coryne mirabilis AG.) 



Among the most common of our Tubularians is a small, mossy 

 Hydroid (Fig. 88), covering the rocks between tides, in patches 

 of several feet in diameter. Fig. 89 represents a single head 

 from this little mossy tuft greatly magnified, in which is seen the 

 medusa bud arising from the stem by the process already de- 

 scribed in the other Hydroids. In Fig. 90 we have the little 



Fig. 88. 



Fig. 90. 



Jelly-fish in its adult condition, about the size of a small walnut, 

 with a wide circular opening, through which passes the long pro- 



Fig. 88. Colony of Coryne ; natural size. (Agassi*.) 



Fig. 89. Magnified head of Coryne , a stem, t tentacles, o mouth, v body, d Medusa. (Ayassiz.) 



Fig. 90. Free Medusa of Coryne. (Ayassiz.) 



