82 NOTES ON 
approaching to blackness. The true form of 
this organ is difficult to determine. Mr. Baker 
gives it the shape of two kidney-beans placed 
parallel to each other, and united at their lower 
extremities. When viewed laterally it appears 
round, while in some other positions it is 
square. 
On each side of the eye are inserted the 
antennee ; the superior pair is longer than the 
inferior ones. They are composed of numerous 
articulations, from each of which proceed two 
or more setaceous bristles. In some species the 
form of these organs distinguishes the sexes, as 
in the Cyclops rubens, the males haying their 
right antenne enlarged, forming a bulb about 
the middle, as shown in figure 4 of the same 
plate. 
These creatures move by sudden starts, 
though they creep along the stalks of plants, 
in which they appear assisted by the feet or 
branchee (a). These members, however, are 
generally in motion, from which it is difficult to 
observe their precise form while the animal is 
alive. One of them on a larger scale is shown at 
figure 3. They are mostly pellucid, but occa- 
sionally of a greenish blue colour. 
