HYDROSTATICA. 383 
ORDER I. 
HYDROSTATICA. 
The Hydrostatic Acalepha are known by one or more 
bladders usually filled with air, by means of which they sus- 
pend themselves in their liquid element. Excessively nume- 
rous and variously shaped appendages, some of which proba- 
bly serve as suckers, and the others perhaps as ovaries, and 
some longer than the rest as tentacula, are attached to these 
vesicles and compose the whole apparent organization of these 
animals. They have no apparent mouth or one which can 
be decidedly considered as such. 
Puysaia, Lam. 
The Physaliz resemble an extremely large oblong bladder eleva- 
ted superiorly into an oblique and wrinkled crest, and furnished be- 
neath, near one of its extremities, with numerous, cylindrical, fleshy 
productions, variously terminated, that communicate with the blad- 
der. Those in the middle give origin to more or less numerous 
groups of little filaments; the lateral ones are merely divided into 
two threads, one of which is frequently very long. There appears 
to be an extremely small orifice in one of the extremities of the blad- 
der, but internally no other intestine is found, but another bladder 
with thinner parietes, and ceca that partly extend into the cavities 
of the crest. There is no nervous, circulating, nor glandular sys- 
tem(1). The animal swims on the surface of the sea when it is 
calm, employing its crest as a sail. When living, itis also fur- 
nished with extremely long filaments, more slender than the others, 
which are sprinkled, as it were, with pearls or drops. Its touch is 
said to sting and burn like that of the Sea-nettle. 
They are found in all the seas of hot climates(2). 
(1) Ihave satisfied myself of this total absence of internal and complicated 
organs in many large individuals, so that I cannot admit the recent idea that the 
Physalia may be one of the Mollusca. 
(2) Holothuria physalis, L.; Amen., Ac., IV, iii, 6; Sloane, Jam., I, iv, 5;—Me- 
