q 
228 Report of the Microscopical Section. [Sess, 
hinge, thus allowing the shell to be opened and shut at the 
will of the creature. The shell is thickly studded over by 
small dots, which on close examination by a high power of the” 
microscope appear as protuberances crowned by a minute hair. 
The shell is very brittle, and seems to be covered by some 
substance which repels the water: it may be that the 
protuberances in question are of use in this respect. 
The mouth is situate on the under surface of the anterior 
lobe of the body, and consists of a superior and inferior lip, 
a pair of mandibles bearing each a palpus, and two pairs of 
jaws. The mandible is a powerful organ for such a minute 
animal: it consists of two parts——the mandible proper, 
terminated at one end by a sharp point and at the other by 
four or five pretty strong teeth; and the palpus, which springs 
from about the middle of the mandible proper, and consists of 
three joints and several sete. The use of these palpi is 
understood to be to cause a current in the water for the 
purpose of carrying its food to the mouth of the animal. 
There are two pairs of antenne: the superior pair, springing 
from the head immediately below the eye, are branched and 
beautifully plumose. 
Cypris is more or less common in ponds and ditches of 
fresh water where the water is stagnant but not putrid. 
Cyclops—The Cyclops is classed under the Cyclopide, one : 
of the families of the order Copepoda or oar-footed animals. 
It is also a one-eyed animal, and is found in fresh water, 
in ponds, lakes, &. The species studied was the Cyclops 
quadricornis. A 
The Cyclops is a pretty little creature, about the one-tenth 
of an inch in length, including the appendages of the tail. 
Viewed externally, it appears to be divided into two distinet 
parts—the thorax and abdomen. The thorax is divided into 
four segments, of which the anterior is equal in size to the 
remaining three: the abdomen is divided into six segments, 
but in the female the second and third are so united as to 
appear but one. The shell of the various segments of the 
thorax is open on the ventral aspect of the animal, to give — 
passage to the feet, the organs of the mouth, and the antenna. 
The single eye is situate in the anterior part of the first seg- 
ment of the thorax, between the superior antenne. These — 
