HYDROSTATICA. 385 
which also depends a kind of garland that crosses all the preceding 
parts. The united contraction of these vesicles enable the animal to 
move rapidly(1). In 
CuPpuwuLitTa, 
The vesicles are regularly attached to the two sides of a frequently 
very long axis(2). 
Racemipa, Cuy. 
Where all the vesicles are globular and small; each one is fur- 
nished with a little membrane, and they are united in an oval mass 
which moves by their joint contractions(3). 
Ruizopuyza, Per. 
Where there are no lateral vesicles but merely a superior bladder 
and an elongated stem, along which the tentacula are suspended, 
some conical and the others filiform(4). The 
STEPHANOMIA, Per. 
Appears to be a third combination, where the lateral bladders, 
which, in Physsophora proper, adhere to the top of the stem above 
the tentacula, extend along its length and intermingle with tentacula 
of various forms(5). 
(1) Quoy and Gaym., An. des Sc. Nat., X, pl. 10, 4, A, f. 1—12. 
N.B. The Glebe of Otto, Ac. Nat. Cur., XI, p. I, Bi 42, f. 3, is merely a vesicle 
of a Hippopus. 
(2) Voy. de Freycin., Zool., pl. 87, f. 15. 
(3) A new genus from the Mediterranean. 
(4) Physsophora filiformis, Forsk., XXXI0, F; Encyc., LXXXIX, 12; the same 
as the Rhizophyza planestoma, Pér., Voy., XXIX, 3. MM. Quoy and Gaymard, 
however, think that these Rhizophyze are merely Physsophore which have lost 
their lateral bladders. 
(5) Stephanomia Amphitritis, Péron, Voy., XXIX, 5. The Stephanomia uvaria, 
Lesueur, appears to me to approximate nearer to Physsophora proper. 
Vou. IV.—2 Y 
