﻿104 



PROCEEDINGS OF THE 



[April, 1857. 



that our own rich shores have been so little interrogated for an- 

 swers to the interesting questions which their history raises. 



On the Medusae of the United States, North or South, I believe 

 there has been, until the present time, but a single special publi- 

 cation, and that consists of the two beautiful and valuable papers 

 by Prof. Agassiz, entitled " Contributions towards a knowledge of 

 the Acalephae of the United States," Besides these, I am ac- 

 quainted with only a very few desultory notices and descriptions, 

 no native American Naturalist appearing to have turned his atten- 

 tion this way with any connected plan of research. 



Yet so abundant are our Southern coasts in genera and species, 

 that one might easily spend the greater portion of his life-time in 

 investigating their astonishing variety, and the singular phases of 

 their history. In a single locality, at the mouth of Charleston 

 harbor, 1 have collected during the past summer (1856) nineteen 

 species of Naked-eyed Medusa, belonging to fourteen genera, and I 

 still feel quite satisfied that more are to be found. Among them 

 was discovered a new and unsuspected instance of " Homogony" 

 besides ample opportunity of throwing light on the method of de' 

 velopment already known. 



An account of the development of O. Turritopsis nutricula has 

 already been given. I now proceed to present a descriptive 

 account of our species, {all of which are new), hoping hereafter to 

 devote a special paper to a more detailed account of the history 

 and structure of each genus. Of these genera the greater number 

 are new to our American Fauna. 



It has been customary among naturalists to separate in descrip- 

 tion the Hydroidea from the Acalephae. The historical connection 

 of the two groups is of itself something so wonderful, as to make it 

 difficult to bring ourselves to an implicit reliance upon it as a gene- 

 ral truth, and the somewhat discrepant observations upon which 

 our conclusions are to be founded have, no doubt, contributed to the 

 same result. The fact, however, that the Hydroidea are all larval 

 or low forms of Medusae, there is no longer any good reason to 

 doubt. There have been so many observations by Sars, Dalyeli, 

 Van Beneden, Loven Steenstrup, Dujardin, Siebold, Agassiz, K61- 

 liker and others, all tending to demonstrate the impossibility of 

 separating these two groups in a natural classification, that scarcely 

 more is needed. However, to my mind, the difficulty felt by some 

 authors in the persistent individual-independence of the polyp-form 

 ir. Tubularia, Camoanularia, &c, is completely explained away by 



