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Ti: XT-BOOK OF A' A "I'O.MOLOGY 



the coxa. It is attached to the epimerum, and is best developed in 

 Panorpidae, Trichoptera, and Lepidoptera. In the Thysanura the 

 trochantine is wanting, and in the cockroach it merely forms a sub- 

 division of the coxa, its use being to support the latter. The second 

 segment is the trochanter, a more or less short spherical joint on 

 which the leg proper turns; in the parasitic groups (Ichneumonidse, 



A 2 



FIG. 102. External anatomy of the trunk of Ifydi-i'ntx ]>i<.-enx: A, sternal B, tergal aspect; 

 2, pronotum; 2 a, prosternum; 2/, episternuin ; :i a. pra-scutum ; :< />. scutum; 8 c. scutelliim : 

 8 d, postscutellum ; 8 g, mesosternum ; 8 A, episternuin; Sf, epimerum; 3 ', crest of the meso- 

 Bternum ; 8 a, parapteron ; 3 k, coxa; 4<i, metapra'scutum ; 46, nu't:iM i utiiin ; 4 c, metascutelliiin ; 

 4 d, postscutellum ; 4 e, tegula ; 4/, episternuin ; 4 /t, epimerum ; 4 (/. menisternum ; 4 i, crest of 

 metastermnn ; 4& and I, coxa; 4 m, trochanter ; n, femur; o, tibia; j>, tursu> ; 7. unguis ; 7-11, 

 abdominal segments. After Newport. 



etc., Fig. 104) it is usually divided into two pieces, though there are 

 some exceptions. The trochanter is succeeded by the femur, tilii, 

 and tarsxft, the latter consisting of from one to five segments, the 

 normal number being five. Tuffen West believed that the pulvillus 

 is the homologue of an additional tarsal joint, "a sixth tarsal joint." 

 The last tarsal segment ends in a pair of freely movable claws 

 (ungues), which are modified setse ; between the claws is a cushion- 



