382 Account of the Meduse of the Genus Equoree. 
Every thing that has been now advanced as to the respi- 
ration of the medusz, supposes that there does not exist. 
in them any kind of apparent respiratory organ, and this 
in fact is the case with the greatest part of these singular 
animals: there are several, however, which form an im- 
portant exception to this rule, and which are evidently pro- 
vided with gills more or less perfect. The equorez in this 
respect present a set of very curious observations, In 
fact, in those which constitute our tirst sub-genus, we 
see at first a singular circle of simple lines, which we 
have described in another place, and which are to be 
met with in a very small number of other meduse ; soon 
these lines extend, develop, and are transformed into fol- 
licules, and into folds so numerous, so delicate and flext- 
ble, that we cannot longer doubt that they perform an im- 
portant part in the history of those animals which have 
received them from nature; and when, upon a closer in- 
spection of these organs, we discover, as Forskahl has al- 
ready done, that these follicules are susceptible on being 
brought together in pairs of forming a multitude of canals, 
through which water may circulate from the edge of the 
umbrella to the base of the stomach, it is very sceptical 
not to regard these innumerable follicules as so many true 
bronchiz, perfectly analogous in their structure, distribu- 
tion, and use, to those of several other marine animals. 
Thus, it is not only upon a numerous and incontestable 
series of analogies that the fact of the respiration of the 
medusz is founded; the very existence of the organs ap- 
propriated to this function cannot leave any reasonable 
doubt as to the important discovery which we have made. 
We may even add, in order to remove all kind of uncer- 
tainty as to this grand fact in natural history, that there 
are species of medusz of an organization still more com- 
plex than those above described, and in which we may 
easily follow all the details of the respiratory system. Such 
are among others the rhizostomes, the aurelli@, the cya- 
vee, the chrysaore, and most of the other polystome 
medusze. When we come to speak of these last, we shall 
exhibit in a series of engravings evcry part of the mecha- 
wism of this important function, of which the equoresg 
furnish but an imperfect illustration. 
, [Pa be continued J 
LXKVI.” Re- 
