ON TRACHEAN ARACHNID A. 
513 
each side a small simple eye, placed a little obliquely. 
Another, but a very small plate, covers the second segment, 
that one which supports the second pair of feet. The rest of 
the body is soft, forms an oblong oval, and is composed often 
rings, which are simply folds of the skin ; the third and fourth 
serve as an attachment for the four posterior feet. 
These four feet, as well as the preceding two, are united in 
pairs, at their origin, by means of a common transverse arti- 
culation, divided in its middle by a depressed line, and cor- 
responding to the maxillary articulation of the first two feet, 
and of the palpi. There is no sternum properly so called, the 
space which occupies its place being taken up by this series 
of radical articulations. These six feet, the lengths of which 
augment progressively, present, as usual, those parts which 
are distinguished by the names of haunch, thigh, leg, and 
tarsus. The haunch is composed of two very short articula- 
tions ; the thigh and leg are long, and of a single piece ; the 
tarsus, more slender, as well as the leg, is divided into three 
articulations, the first of which is very long, and the last very 
short ; at the superior extremity of this last are implanted two 
filiform appendages, arched, hairy, similar to two fingers, and 
each terminated by a small scaly hook. All these divers arti- 
culations are cylindrical. 
The feet are bristling with long hairs, and have here and 
there some small mobile spines. The haunches of the two 
last have, underneath, a range of small scales, very thin, trans- 
parent, and composed each of a pedicle, at the end of which 
is a mobile triangular piece, broad, folded in two, or forming 
an angle, and inclined in some species. These scales might 
be compared to one-half of a funnel, compressed, and cut in 
two, in the direction of its length. They represent, though 
but very remotely, the combs of the scorpions. The abdomen 
is oblong, soft, and more or less hairy, as well as the body, 
and without any appendage, at least any projecting one, at 
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