THE EUROPEAN SEAS. 



143 



treads of the European seas. Of the foregoing 

 forms those marked with an asterisk are also met 

 with in the Red Sea. 



Gyathma pseudo-turhinolia and Balanopliyllia 

 Italica have had a long occupation of the Mediter- 

 ranean region. In like manner our Sphenotrochus 

 Andrewianus had early representatives in such fossil 

 species as S. milletianus and S. intermedins. 



Of the higher division of Medusae, one — the Sea- 

 blubber (Aurelia aurita) — ranges along the western 

 shores of Europe, and throughout the whole of the 

 Mediterranean ; as many as half a dozen reputed 

 species are perhaps referable to this our commonest 

 form. Pelagia, an Atlantic genus, but of the Lusi- 

 tanian zone, just reaches our south-west shores. 

 They are abundantly Mediterranean, and in that sea 

 are so phosphorescent at times, as to show like 

 globes of fire beneath the waters, fflrizostoma, a rare 

 form on our own British coasts, and Ghrysaora, 

 swarm in the Western Mediterranean. 



Of the Medusae we know but little as yet, either 

 of their development, the functions of their several 

 parts, or of their habits and distribution. Sea-going 

 naturalists meet with them in greater numbers 

 than any other forms of life ; at times our internal 

 seas, such as the Irish and English Channels, swarm 

 with them ; they float up into all our estuaries, 

 and if we venture out into the open Atlantic, in ad- 

 vance of our western coasts, Medusce may still be 

 met with. Viewed in this way, certain forms are 



