72 



MARINE ANIMALS OF MASSACHUSETTS BAY. 



Jelly-fish is almost ready to break from its attachment, having 

 assumed its ultimate outline. Fig. 97 represents it just after it 

 has separated from the stem, when it has only two tentacles at 

 each cluster and simple knobs around the mouth, instead of the 

 complicated branching tentacles of the adult. 



Tubularia. ( Tubularia Couihouyi AG.) 



There are several other Tubularians common in our waters 

 which should not be passed over without mention, although as 

 this little book is by no means intended as a complete text-book, 

 but rather as a volume of hints for amateur collectors, we would 

 avoid as much as possible encumbering it with many names, or 

 with descriptions already given in more comprehensive works. 

 This Tubularia is interesting, however, from the fact that the 

 Medusae buds are never freed from the stem, and do not develop 



Fig. 98. Fig. 99. 



into full-grown Jelly-fishes, but always remain abortive. Fig. 98 

 represents one head of such a Hydroid with the Medusas buds 

 pendent from it in a thick cluster, while in Fig. 99 we have a 

 few of them sufficiently magnified to show that, though present 

 ing the four chymiferous tubes, they are otherwise exceedingly 

 simple in structure, as compared with the free Jelly-fishes. 



Fig. 98. Tubularia ; magnified. 



Fig. 99. Part of cluster of Medusas of Fig. 98 ; magnified. (Ayassiz.) 



