82 DISCOPHOR^. Part HI. 



the form, are yet easily noticed. Now, the mode of ramification of the branching 

 chymiferous tubes, the form of the lobes protecting the eyes, the arrangement 

 of the folds of the ovaries and spermaries, the form and position of the digitate 

 appendages of the sexual organs, the mode of insertion of the tentacles along the 

 margin of the disk, the extension of the veil below the tentacles, the character 

 of the fringes along the margin of the mouth and of the arms, are likely to 

 belong to this category. I would therefore considei', in Aurelia, as generic char- 

 acters, the fact that there is a narrow veil along the inner margin of the disk ; 

 that the tentacles are covered with beads of lasso-cells, and arise in sockets 

 between flat, vertical lobules ; that the eyes are protected by two broad-sjireading 

 lappets, which may be bent over the eye-peduncle ; that the margins of the mouth 

 and arms are fringed with small feelers ; that the ovaries and spermaries form 

 a wreath of lobes around the sides of the sexual pouches; that the digitate 

 appendages, consisting of simple fusiform feelers, are arranged in many rows along 

 the folds of the spermaries and ovaries, and occupy a band about as bi'oad as 

 those oi-gans themselves ; that the cavity below the sexual pouches is coextensive 

 with them, but tapers downwards in the shape of an open funnel; and that the 

 branching chymiferous tubes form a network of anastomoses, becoming more and 

 more intimate towards the margin of the disk, where they lose, in a measure, 

 their radiated arrangements, to form a closer network. But if all the points I 

 have here enumerated are truly generic characters, and if the illustrations of the 

 structure of the Aurelia aurita of Europe given by Ehrenberg are correct in their 

 details, I entertain some doubts as to the generic identity of our species and its 

 European representative ; for Ehrenberg represents the eye on a very large scale, 

 and yet his figure does not at all agree with that of our species ; nor do the 

 tentacles appear to be inserted in sockets and separated from one another by 

 distinct lobes, as I have represented them, PI. VII. Figs. 2, 3, and 4. No one 

 of the many observers, who have described the Aurelia aurita of Europe, has made 

 the slightest allusion to the existence of such lobes; nor is the veil below the 

 tentacles mentioned, though it seems to be figured by Ehrenberg in PI. IV. Fig. 1 

 of his paper, while Gegenbaur refers Aurelia to a grouj? of Acalephs, his Acras- 

 peda, which he characterizes as destitute of a veil. Again, Ehrenberg's represen- 

 tation of the appearance of the marginal feelers of the arms, in his Plate VIII. 

 Fi(/. 1, does not agree with what I have seen and ' represented in our species 

 (PI. VII. Fiff. 7, and PI. VIII. Fig. 9). Whether these discrepancies indicate generic 

 differences, such as I consider the insertion of the tentacles in the sockets, and 

 the presence of distinct and comparatively large flat lobes between the tentacles 

 to be, or only specific differences, such as I consider the club-shaped fingers of 

 the arms of the European species, compared to the pointed fingers of our species 



