MORPHOLOGY OF THE GENITAL ARMATURE 



179 



segment is not distinctly shown in Klapalek's sketch. The origin 

 of these elements of the genital armature evidently needs further 

 study. 



Whether the abdominal legs or so-called false or prop-legs of 

 lepidopterous larvae are genuine legs, homologous with those of 

 the thorax and with the cephalic appendages, or whether they are 

 secondary adaptive structures, is a matter still under discussion. 

 That, however, they are true legs is shown by the embryology of the 

 Lepidoptera, where there is a pair to each abdominal segment. It 

 may also be asked whether the anal legs of lepidopterous larvae 



sc 



md.p 



FIG. 201. Eriocephala cahhella, tf, side view: t, palpiform suranal plate; cl, claspers; 

 s, inferior claspers ; mxp, maxillary palpi ; ex. coxa ; tr, trochanter ; sc, scutum ; sc', scutellutn. 



are not the homologues of the 2-jointed anal appendages of caddis- 

 worms. 



In Lepidoptera, notably the male of the very generalized Erioceph- 

 ala calthdla (Fig. 201), besides the broad unjointed claspers, which 

 are curved upward and provided with a brush of stiff hooked setae 

 (this upper pair being perhaps modified cercopods), there is an 

 accessory lower slenderer pair, while the suranal plate (f) is palpi- 

 form or clavate and also adapted to aid in the action of the claspers. 

 The examination of the cercopods and rhabdopods in the Trichop- 

 tera and in a generalized lepidopterous form like this enables one 

 to understand the morphology of the genital armature, since it 

 consists, besides the suranal plate, which is often deeply forked (in 

 Sphingidae, Smith), of a pair of modified hook-like cercopoda, and 

 in some cases (Eriocephala) of an additional pair of claspers which 



