ON TRACHEAN ARACHNIDA. 
523 
would represent the principal parts of the mouth of the insects. 
The siphon of the nymphons exhibits no division at its sur- 
face. 2. In this last genus, the first articulation of the body 
is narrowed a little in front of the insertion of the two anterior 
feet, and of the two oviferous feet ; then it is prolonged and 
dilated insensibly, in the manner of a neck, or obconical pedicle, 
the anterior extremity of which serves as a support to the 
mandibles. This support is formed by the union of the radical 
articulation of each of these mandibles. These two articula- 
tions, intimately united, and dilated infcriorly, embrace the 
anterior extremity of the pedicle in the manner of a collar. 
The tubercle supporting the four eyes is situated at the pos- 
terior and dorsal extremity of the first segment behind the 
pedicle ; but in the phoxichili, the first segment of the body 
is short and transverse, so that the two anterior feet, and the 
oviferous feet are inserted near the origin of the siphon. At 
the posterior and dorsal extremity of this part, are set back to 
back, and united longitudinally, the two radical articulations 
of the mandibles. The tubercle supporting the eyes, is 
situated between this common articulation and the following; 
the mandibles, exclusive of the support we have just men- 
tioned, seem to take their origin from the anterior base of the 
oculiferous tubercle. 3. We see, on each side of the base of 
the siphon, in front of the insertion of the oviferous feet, a 
small articulation in the form of a rounded tubercle. 4. The 
feet, less elongated proportion ably than those of the nymphons, 
have an articulation less than the latter, that is to say, eight, 
the lateral and projecting prolongations of the segments of 
the body included, instead of nine, the one which in the 
nymphons forms the last but one, or the eighth, being here 
almost insensible. The oviferous feet of the phoxichili re- 
semble in tlieir form and proportions, those of the nymphons. 
They are composed of ten articulations, as well as in this 
last genus ; the mandibles are filiform, and terminate a little 
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