78 DISCOPHOR^. Part III. 



according to the weather, and towards the end of the spring, if we can speak of 

 a spring in this climate, the young Ephyras are set free, and soon afterwards appear 

 near the surface as small Aurelias, which the approaching summer soon brings to 

 their adult state. 



SECTION VII. 



NOMENCLATURE OF AURELIA. 



The type of DiscophorJB, to which the genus Aurelia belongs, constitutes a natural 

 family, the species of which are very similar among themselves, and distributed 

 in all the seas. Some of them have been described over and over again, in differ- 

 ent stages of growth, and in different states of preservation, and erroneously con- 

 sidered as distinct species, and even as distinct genera. In consequence of these 

 mistakes, the synonjnny of these animals is very complicated, and the more difficult 

 to decipher, as most descriptions of these Medusse are very imperfect. Leaving 

 out of consideration the genera Scyphostoma, Strobila, and Ephyra, which are now 

 known to have been founded upon various stages of development of different spe- 

 cies, belonging even to different genera, we find, in different authors, Medusae of 

 this family described under the generic names of Medusa, Aurelia, Claustra, Ocyroe, 

 Biblis, Macrostoma, Evagora, Orythia, Cyanea, Monocraspedon, and Dijilocraspedon. 

 Some of them have even been referred to the genus Rhizostoma. Notwithstanding 

 the apparent diversity which might be supposed to exist among them, if we look 

 only upon this array of names, I am unable to distinguish more than one genus 

 among them all, unless the difference mentioned by Brandt, upon which he has 

 distinguished the genus Diplocraspedon, really indicates a different genus. That 

 Scyphostoma is only the earliest stage of tlie Hydra of different Discophoraj has 

 already been shown, while the great similarity of the Scyphostoma of our Aurelia 

 and that of our Cyanea is at once apparent, upon comparing the figures of Plates 

 X. and X^ Vol. III. The Strobila state of Aurelia and of Cyanea are equally 

 similar, and we shall see presently that the Ephyrte of Pelagia resemble, to the 

 same extent, those of Aurelia. 



It is a great misfortune that Eschscholtz and DeBlainville published their works 

 upon Acalephs at the same time, and still more, that when DeBlainville reprinted 

 separately his article "Zoophytes," of the " Dictionnaire des Sciences Naturelles, 

 Vol. 60," under the title of " Manuel dActinologie," he did not harmonize his nomen- 

 clature with that of Eschscholtz. The consequence was, that in France, the tra- 

 dition of Peron and LeSueur was kept up through DeBlainville, and, afterwards. 



