56 



MARINE ANIMALS OF MASSACHUSETTS BAY. 



Fig. 69. 



Eucope, which darts through the water at full speed, hardly stop- 

 ping to rest for a moment. If the Oceania be disturbed it flattens 

 its disk, and folds itself up somewhat in the shape of a bale (see 

 Fig. 69), remaining perfectly still, with the tentacles stretching 

 in every direction. When the cause of alarm is removed, it 



gently expands again, re- 

 suming its natural outline 

 and indolent attitudes. The 

 number of these animals is 

 amazing. At certain sea- 

 sons, when the weather is 

 favorable, the surface of the 

 sea may be covered with 

 them, for several miles, so 

 thickly that their disks 

 touch each other. Thus they remain packed together in a dense 

 mass, allowing themselves to be gently drifted along by the 

 tide till the sun loses its intensity, when they retire to deeper 

 waters. Some points, not yet observed, are still wanting to com- 

 plete the history of this Jelly-fish. By comparing such facts, 

 however, as are already collected respecting it, with our fuller 

 knowledge of the same process of growth in the Eucope, Tima, 

 and Melicertum, we may form a tolerably correct idea of its de- 

 velopment. It is hatched from a Campanularia. 



Clytia. (Clytia hicophora Ac.) 



In Figs. 70 - 73 we have the Acalephian and Hydroid stages 

 of the Clytia (Fig. 73), another very pretty little Jelly-fish, closely 

 allied to the Oceania. When first hatched, like the Oceania, it is 

 very convex, almost thimble-shaped (see Fig. 70), but a little 

 later the disk flattens and becomes more open, as in Fig. 71. In 

 Fig. 72, we have a branch of the Hydroid, a Campanularia, 

 greatly magnified, with the annulated reproductive calycle at- 

 tached to it, and crowded with Jelly-fishes ready to make their 

 escape as soon as the calycle bursts. The adult Clytia (Fig. 73) 

 is somewhat smaller and more active than the Oceania, and 



Fig. 69. Attitude assumed by Oceania when disturbed. 



