580 



MEDUSA OF THE WORLD. 



Synopsis of the "Species" of Chrysaora Continued. 



*This species shows a tendency to approach the Dactylomctra stage in having 48 marginal lappets, but the tentacles remain 

 24 in number as in other species of Chrysaora. L. Agassiz, 1861, calls this Melanasler mertensii. 



medusa is highly variable in color, sometimes pale, nearly uniform, milky ocher-yellow, and 

 at other times with radiating streaks of rich red-brown. 



The medusa is locally common but rare in many other places, such as Naples, where 

 it is hardly ever seen. 



According to Graeffe, C. hysoscflla is found at Trieste, Adriatic Sea, from November to 

 April, and is mature in winter. It is hermaphroditic, and the eggs segment in the ovaries and 

 are set free as pear-shaped planulze in March and April. At the end of 8 to 14 days they become 

 attached by the broad anterior end and finally acquire 16 tentacles in the scyphostoma-stage. 

 These strobilate in September and October and each gives rise to 8 to 12 ephyrae. 



