JELLY FISHES VARIETY AND BEAUTY. 105 



When closely examined, the float is found to be of 

 very elaborate structure. Instead of being a simple 

 cartilaginous disc as it appears at first sight to be, it is 

 composed of a series of extremely thin circular plates, 

 each succeeding one being larger than its predecessor. 

 Each plate is scalloped round the edge, and marked with 

 delicate lines, some radiating from the centre to the 

 circumference, and others forming concentric circles, so 

 as to produce a pattern very like the web of the garden 

 spider. 



The disc thus formed constitutes the skeleton if we 

 may employ such a word of the animal, and it is 

 clothed with a delicate membrane, falling into slight 

 folds, nearly transparent, and of a lovely blue or purple 

 colour. Surrounding the disc are the tentacles, which 

 are set closely together and nearly cylindrical, though 

 they enlarge slightly towards their tips. 



As the disc does not pulsate, and the tentacles merely 

 float in the water, the Porpita has no power of locomo- 

 tion, and merely floats wherever the waves may happen 

 to carry it. When thus displayed, it forms a most 

 beautiful object. Lesson, in describing a species which 

 he discovered (Pwpita Padfica) says that it resembles a 

 small blue passion-flower as it floats on the water. Vast 

 numbers of this creature are seen in company with each 

 other, and Lesson saw the Porpitas in such fleets that 

 they were closely pressed together, and covered the sea 

 like a large sheet of ice. 



Similarly possessed of a cartilaginous skeleton, the 



