GENERA. 17 
gemmation, and a very remarkable and quite novel one, I have discovered in another form of 
Sarsia, taken abundantly in 1836 on the coast of Cornwall, and named by me Sarsia prolifera. 
In this extraordinary animal the buds are produced at the bases or tubercles of the four marginal 
tentacles, and hang from them in bunches, like grapes. The degree of development is not 
equal in all four bunches, and in each case buds are seen in very various stages of develop- 
ment, from embryo wart-like sproutings to miniature Medusze, simulating in their essential 
characters the parent animal. [See figures and description of Sarsia prolifera in the synopsis 
of the species. | 
I look upon this last discovery as very important in its bearing on the history of this 
phenomenon of gemmation among these creatures, seeing that in the case under consideration the 
seat of reproduction is not in the peduncle, where in Sarsza the true ovaries might be supposed 
to be seated, since they are not manifest elsewhere, but in a portion of the animal quite apart. 
It would appear, indeed, that gemmation can occur anywhere in the course of the granular 
motor tissue, or from the true ovaries, but not from other than the motor, and especially 
reproductive, tissues. The power of the motor tissue to produce germs occurs also in other 
orders of Medusze: for I have seen the same phenomenon in the Beroe. When treating of 
the phosphorescence of the naked-eyed Medusee, we have seen that that phenomenon was 
exhibited either by the ovaries, or centre (peduncle) or bases of the tentacles and rim; all, as 
I have just proved, seats of reproductive power. This goes far to connect that phenomenon 
with the generative functions. 
The development of the ovum in the naked-eyed Medusze has still to be observed. Not 
until the phenomena attending it have been made known, can we hope to ascertain the history 
of the metamorphoses which they possibly, indeed most probably, undergo before arriving at 
the state in which we usually find them. 
The preceding outline of the structure and physiology of the naked-eyed Meduse, so far 
as known, will enable the reader to understand the detailed account of our British genera and 
species, which I shall now proceed to give, reserving remarks on their zoological affinities as 
a group, for a review of the subject at the conclusion of the synopsis, when we shall have 
the necessary evidence before us. 
There are forty-three species of Gymnopthalmatous Pulmograda known to the author 
as inhabiting the British seas. The greater number of these are undescribed forms. They 
may all be arranged under eighteen Genera, grouped together as in the following table : 
I. Vessels branched. (WILLSIADZ.) 
1. Willsia. 
II. Vessels simple; ovaries convoluted, and lining the pedunculated stomach. 
(OCEANID@.) 
2. Turris. 
3. Saphenia. 
4. Oceania. 
III. Vessels simple, eight or more; ovaries linear, in the course of the vessels on the 
sub-umbrella. (AJ@UOREAD®.) 
5. Stomobrachium. 
6. Polyxenia. 
