386 Dr. Du Plessis on a new Paludicolous Medusa. 
that of which we now speak, even as regards the phy¬ 
siognomy of the vegetation; for in both places a cincture of 
murmuring reeds fringes the banks, and the surface shows 
great accumulations forming actual islets of brown and green 
marine Algfe. These are Confervacem of the genera Chceto- 
phora , Cladophora , Bryopsis , &c. These mingled masses 
harbour a multitude of creatures of all the divisions of the 
animal kingdom from fishes to Zoophytes, Infusoria, and 
Rhizopods. 
It was in exploring the floating islets that we discovered, in 
the middle of the canal, halfway between Cette and Agde, 
the creatures under consideration. These little bells were 
always found suspended by their long tentacles from the 
lower surfaces of the masses of Algae. They thus found food 
and shelter, protected from the sun. 
In fact this is the place to remark that, in the summer 
months, the water of this long shallow canal, flanked by hot 
sands and without any shade, is almost all day long exposed 
to the burning sun of Languedoc, and often exceeds 25° C. 
(77° F.) in temperature. When the arms or legs are im¬ 
mersed in it the impression of a tepid bath is produced. 
Moreover this water is very brackish. In the first place it 
is recruited by the pool of Thau, which is itself very far from 
being pure sea-water. This lagoon receives the southern 
canal, Avhich opens into it near Agde, and pours into it an 
immense quantity of fresh water ; several small streams and 
the springs of l’Abime and Enversac also discharge into it. 
Rut, in addition, the canal of the salt-works is constantly 
receiving the mother liquor of the pans from which the salt 
has been obtained ; frequently the canal is overflowing with 
water which is sea-water less the salt, that is to say, without 
its essential part. The strength and concentration of this 
brine vary according to the state of the works, the dryness or 
humidity of the season, storms, &c. In summer it is very 
concentrated, in winter very dilute. 
How could we expect at so many leagues from the sea, and 
with no communication with it except through the immense 
lagoon of Thau, to find a Medusa, that is to say, one of the 
creatures most difficult to suit in the matter of its watery 
medium ? 
Every zoologist who has attempted to keep these creatures 
in captivity has been reduced to despair by seeing them 
perish in a little time, whatever may have been done to 
render the aquarium comfortable for them. But this marsh 
species that we had just discovered, forced, no doubt, by vital 
competition to accommodate itself very gradually to great 
