424 ACALEPHA. 
met with collected in great numbers-and swimming in the same 
direction, with their body inclined obliquely. 
The Cerne®, Pér., are only distinguished from the other Rhizos- 
toma by having filaments intermixed with the dentations of the pedi- 
cle*, 
The Casstopex have no pedicle, properly so called; their (usually 
eight) arms, which are sometimes ramous, arise directly from the in- 
ferior surface ft. 
In other species, without a central mouth, we find none of those 
numerous ramifications in the pedicle, nor open cavities for lodging 
the ovaries. They might be united under the name of 
ASTOMA. 
Some, however—LymnoreEa and Favonia, Pér.—still have a large 
pedicle furnished on each side with fibrous, filaments which may act 
as suckers. 
Others—GeryoniA, proper, Pér.—are even destitute of these fila- 
ments, but have an infundibuliform membrane at the extremity of the 
pedicle, from the bottom of which vessels seem to arise that ascend 
into the pedicle and spread out through the umbella. 
One of them is found in the Mediterranean, the Med. probos- 
cidalis, Forsk., XXXVI, 1}. 
Oriruyi, Peér., 
Where that membrane is wanting §. 
Berenix, Pér. ||, 
Where there is no pedicle whatever, but where the inferior surface 
appears to be provided with little suckers along the track of the ves- 
sels ¥. 
pulmo, Gm., Macri, Polm. Mar. I, B; Borlasse, XXV,15. See Eisenh., Ac. Nat. 
Cur. X, part II, p. 377. 
The Potta marina, Aldroy., Ib., p. 576, is perhaps another species. 
I suspect that the EpHira, Pér.,— Medusa simplex, Pennant; Borlasse, Cornw., 
XXV, 13, 14—is merely a Rhizostoma deprived of its pedicle. 
The Medusa pileata, Forsk., of which Péron makes an Oceania, has the ramous 
pedicle of Rhizostoma proper, but enclosed under a campanulate umbella, furnished 
at the margin with tentacula. 
* Medusa cephea, Forsk., XXIX; Encyc., XCII, 3, 4;—Med. octostyla, Id., XXX, 
Encye., Ib., 4;—Med ocellata, Modeer., Noy. Act. Holm., 1791. 
+ Med. frondosa, Pall., Spic., X,<i, 1, 3;—Med. octopus, Gm.; Borlasse, XXV, 
16, 17;—Med. andromeda, Forsk., XXX1?— Med. corona, Id., p. 107?—Rhizostoma 
leptopus, Chamiss. and Eisenhardt, Ac. Nat. Cur., X, p. I, pl. xxviii, f. 1;—Cass. 
borbonica, Delle Chiaie, Mem., I, tab. 3, 4. 
t Add Dianée Gabert, Zool., Freycin. pl. 84, f. 2; Geryonia tetraphylia, Chamiss. 
and Eisenh., loc. cit. f. 2. 
§ Medusa minima, Baster, Op. Subs., I11;—Dianée dubaul, Zool., Freycin., pl. 84, 
f. 3, which is the Geryonie dinéme, Pér. It is possible that mutilated Geryoniv 
(which are often in that condition) may have been taken for Orythyie. 
ll Cuvierta carisochroma, Pér., Voy. aux Terres Aust., XXX, 2. 
{ Medusa marsupialis, Gm., Plancus, Conch., Min, Not,, 1V, 5;—Carybdea peri- 
phylla, Péron, 
