ON TRACHEAN ARACHNIDA. 523 



would represent the principal parts of the mouth of the insects. 

 The siphon of the nymplioiis 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 inferiorly, 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 sijDhon, in front of the insertion of the oviferous feet, a 

 small articulation in the form of a rounded tubercle. 4. The 

 feet, less elongated proportionably 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 their 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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