110 D1SC0PH0R.E. Part III. 



Incompletely as these facts represent the history of the growth of our Cyanea, 

 they are already important in a systematic point of view, for they show how 

 cautious naturalists should be in characterizing genera and species by the number 

 and form of the appendages of the lower floor. On examining the many illus- 

 trations of similar animals, which have thus far been published, I find that Brandt, 

 in describing the species observed by Mertens, of which he has given an account 

 in the Memoirs of the Academy of Sciences in St. Petersburg, for the year 1838, 

 characterizes as a distinct genus, under the name of Cyaneopsis, a small Medusa 

 of this family, which I believe to be only the young of the species represented in 

 the same work, under the name of Cyanea Postelsii. Mertens himself had con- 

 sidered it as a variety of that species. The close resemblance of this Medusa 

 with specimens of Cyanea versicolor of about the same age, observed in Charleston, 

 leaves no doubt in my mind that the genus Cyaneopsis is only founded upon the 

 peculiarities exhibited by young specimens of Cyanea. 



Though unable, upon a renewed examination of my notes, to verify the fact, 

 I would, nevertheless, call attention to the circumstance, that in the drawings of 

 the youngest Cyanea versicolor which I possess, the tentacles are represented as 

 three in number in each lobe, the middle one being by far the largest; and so 

 it is also in the Cyaneopsis Behringiaua of Brandt, while in the youngest Cyanea 

 arctica, observed by my son, there are two large tentacles to four small ones, in 

 each bunch. In the youngest Cyanea fulva there are also three tentacles to each 

 bunch, while in somewhat older ones, there are three in some bunches and four 

 in some others. This seems to indicate an inequality in the mode of develop- 

 ment; but whether it is individual or specific, I am unable to say. 



We have already mentioned that the yovmg Cyanea arctica resembles the adult 

 in its coloration. The same is also the case with the Charleston species; its 

 brilliant pink or rose-colored tentacles give it an appearance ver^^ diflerent from 

 that of the young of the other species, in which the tentacles are of the same 

 tint as the disk. The rosy color of Cyanea versicolor is, however, limited to the 

 lining of the cavity of the tentacles, the walls themselves being perfectly white 

 and transparent. The upper surface of the disk is covered with hollow papillte, 

 of which those in the centre of the disk are the largest; near the margin they 

 are more numerous and very minute, and seem most crowded in the direction of 

 the radiating pouches. 



The youngest specimen of Cyanea versicolor seen by me was found swimming 

 near shore, in the channel along Sullivan's Island, in Charleston harbor, and was 

 kept for some time in confinement. It often suspended itself, by the folds of the 

 actinostome, to the sides of the glass vessel in which it was kept, and I am led 

 to infer, from this circumstance, that this is a natural habit of the young CyaneaB, 



