M. Hesse on a new Parasitic Crustacean. 75 
The whole of this apparatus is strongly attached to the inte- 
rior by very apparent muscular ligaments, by means of which it 
is continually issuing from and returning into the proboscis. 
Lastly, we also see beneath this proboscis—that is to say, at 
the base of the buccal apparatus just described—a pair of very 
strong footjaws, composed of three joints, and terminated by a 
strong, flat, lamellar, and denticulated claw, constructed to dig 
into or cut objects. These footjaws are curved inwards, so as to 
be able to reach or even to pass the apex of the buccal orifice, 
upon which they lower themselves in case of necessity. 
We have also remarked that the eye participates in the move- 
ment tv and fro which causes the buccal apparatus to issue and 
return—an impulse which acts upon the tegumentary envelope 
in which it is fixed; we have likewise ascertained that it is 
capable of an incomplete rotation upon itself. 
The body, which is very opaque, and, in consequence of its 
comparative thickness, conceals from sight the details of its in- 
terior organization, 1s surrounded throughout its whole extent by 
a transparent border, which follows all its outlines. Even with 
the aid of the compressorium we were unable to detect the 
movements of circulation, which nevertheless would have been 
very interesting ; we ascertained only that the intestinal tube, 
which is very voluminous, especially at the middle of the body, 
passes directly from the cesophagus to the anus, and that the 
matters contained in it are black, thick, and syrupous; these 
issue readily from the body when it is touched rather roughly, 
and then, by spreading in the water, form a tolerably compact 
network, which remains for some time without dissolving. 
It was only by infinite patience, and by taking advantage of 
an individual kept alive for more than a fortnight and reduced 
by abstinence until it was nearly transparent, that we succeeded 
in ascertaining the organization of the mouth and its evolutions. 
We had previously attempted in vain to detect them by means of 
the compressorium ; its action upon these organs, crushing them, 
produced nothing but confusion, which prevented our continuing 
our observations. The lobes of the diver are very large, and are 
contained in the middle of the abdominal cavity. We could not 
detect the organs of generation. The ova are large, enclosed 
within the most spacious part of the thoracic region, and placed 
above the intestine while they are still contained in the oviduct. 
They are arranged in a chain in two or three rows, and form a 
considerable number of loops or sinuosities; their course may 
be detected, and is directed towards the orifices placed at the 
base of the last thoracic segment. When they are expelled 
from the body, they form a square flat mass; they are enclosed 
in a special envelope, and agglutinated together. They appear 
6* 
