MEDUSA BIFIDA. Ill 



We have still to look farther, — to dive deeper into the obscure sub- 

 ject before us. 



From one notable peculiarity of the Hydra gdafinosa, Strobila, Tuhu, 

 or by whatever name it shall be recognised, our notice must be now di- 

 rected to an animal of altogether an opposite origin, one entirely different 

 in form, in habits, and in permanence, though between the two there be a 

 union or connection, hitherto insuflficiently understood. 



The figure and the properties of this creature annex it to the Medu- 

 sarian tribes, whose history would admit of long and interesting commen- 

 tary, as seen from a few preceding observations. 



Meantime, I shall consider the being alluded to, nearly as I have 

 viewed the former, that is, chiefly as a perfect and independent animal, or 

 an animal advancing towards perfection, until more versant in its history. 

 Herein there are various obscurities which I cannot pretend to explain. 

 Nevertheless, the curious and inquisitive, whose attention is attracted to 

 them, may be able to offer a satisfactory solution, through some connected 

 chain of facts, of what has appeared to me enigmatical. 



I confine myself entirely to what I have seen. 



Long ago, I had remarked colonies of minute transparent animals, 

 swimming in vessels of sea- water, during the months of February, JVIarch, 

 and April. Their general aspect very much resembled a flock of birds in 

 distant flight, as represented by landscape painters. — PI. XVIII. fig. 1 ; 

 PI. XX. fig. 1. After being transferred to vessels free of other subjects, 

 they continued several days in activity, and then disappeared. I could not 

 account either for their origin or their transience. They occurred only at 

 rare intervals, and always identically under the same form. 



More accurate inspection on these occasions, and subsequently, showed 

 the alliance of such creatures to that comprehensive genus the Medma, 

 both in configuration and in habits. But the date of their appearance 

 did not correspond with the wonted periodical ascent or arrival of that 

 tribe to the surface of the Scotish seas during the summer months. In 

 the year 1826, I found them as early as the 6th of February. 



The whole of this remarkable race is now partitioned into several di- 

 visions, founded on their common aspect or individual properties. But 



