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Transactions of the Society/. 



insignificant. Both the femurs, the tibias, and the first two joints 

 of the tarsi carry several longitudinal rows of stifi^, sparse bristles. 

 The three terminal joints of the tarsi have bristles only on their 

 upper surface. 



The legs increase in length from the first to the last pair. The 

 tarsi of the third pair of legs are much the longest, while those of 

 the second pair are the shortest. The hinder coxae are one-third 

 longer than the coxse of the middle and front legs. The insertion of 

 the legs into the sternum is as follows : : ; , the front pair being 

 distant from the approximating posterior limbs and also further 

 apart laterally from each other. 



The female differs from the male only as regards the legs, by 

 these being but half as long. This is readily seen by the simple 

 inspection of the femurs, tibias, and first joints of the tarsi, in both 

 sexes. 



The ungual, or terminal joint of the tarsus is furnished with 

 two claws, which in the male are deeply cleft or bifid, while in the 

 female they are simple. In both sexes a prominent finger-like fleshy 

 projection of the tarsal joint projects above and between the claws 

 for nearly their length. 



In opposition to this interungual appendage and starting from 

 the opposite angle of the truncate extremity or heel of the tarsal 

 joint, a very remarkable S-shaped comb exists. This singular 

 apparatus ends beyond the apex of the claws. Its outer edge is 

 deeply fringed by a series of lengthened simple as well as forked or 

 bifid teeth, while its inner edge is quite smooth. This tarsal comb 

 is similar in both the male and the female, which proves its use to be 

 ambulatory or adhesive and not sexual. This appendage is hyaline, 

 of glassy aspect. 



Dimensions of the Legs of the Male. 



B. Wings and Halteres. — The rudimentary wings are opaque, 

 linear, and show a constriction at a distance equal to 1/4 of their length, 

 measured from their apex. They are fringed with long hairs on their 



