ORDER ACALEPHA SIMPLICES. 483 
When they have no tentacula around the umbrella, they 
constitute the PHORCYNIA of Lamarck. 
When the umbrella is furnished with tentacula all around, 
it characterizes the AZQUOREA, more particularly so named, 
of Peron, one of the most numerous subgenera, especially in 
the seas of hot climates. Medusa equorea, Gm. &c. &c. 
Certain species are remarkable for lamin, which furnish 
their inferior surface. Others, FovEOLIA, Peron, are signa- 
lized by little fossettes, hollowed in the circumference of the 
umbrella. Medusa mollicina, Forsk., &c. 
We may thus unite under the name of 
PELAGIA, 
Those in which the mouth is prolonged into a peduncle, or 
divided into arms. Pelagia panopyra, Peron. 
In all these subgenera, there are no lateral cavities; but a 
much greater number of these meduse, with simple mouths, 
have in the thickness of the umbrella four organs, formed of 
a plaited membrane, filled at certain periods with an opake 
substance, and which appear to be ovaries. They are most 
frequently lodged in as many cavities, open at the inferior 
face, or on the sides of the pedicle; and which, as I think, 
have been erroneously taken for mouths, because some little 
animals are occasionally caught in them. Some naturalists 
take them for organs of respiration ; but it is more probable 
that this function is exercised on the margins of the umbrella. 
The tentacula, whether of the margin of the umbrella, or the 
circumference of the mouth, vary not only according to the 
species, but even according to age. 
We unite under the name of 
CYANEA, Cuv. 
All the meduse with central mouth, and four lateral ovaries. 
The most extended, Medusa aurita, L. Miill. Zool. Dan. 
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