THE CANADIAN ENTOMOLOGIST 183 



that orrurriiii; in tlic m.ilr of dryllohldlld ((iiv/wdcij'nniii.s, which \\'alker, I'.H'.) 

 ll. c.) consiflcTiMl to \k- iini(|iK' anionic wins^cd insects. 



The ic'h\ti\c positions of the parts in the sawlly (I'lRs. '■] and 2) are essentially 

 th(^ same as in the more priniili\e representati\es of the higher orders of insects, 

 snch .IS the tipulids anions the Diptera. Philaprtamiis among the Trichoptera 

 (.•tc, l)ul other structure become secondarily developed in certain of these forms, 

 ihereliN' rendering the arrangement of the parts much more complicated and 

 diiilirull of interpretation. As was descri];ed in a i)aper on the genitalia of male 

 sawflies (Proc. hjit. So(\ Washington, l',)10, \'ol. 21. p. 129) there become dif- 

 ferentiated from the distal i)ortion of the segment "b" (Fig. 2) of the sawfly's 

 gonopods, a pair of inner elaspers which were interpreted as the volsella? of 

 higher H\-menoptera in the paper referred to above. These ^'olselhe-like struc- 

 ture's probabK' corresiiond to the inner elaspers of such Lepidoptera as the 

 ( 'ieometri(he, etc. One or both of tlu- \al\es of the penis "d" may form a portion 

 of the aedeagus; and numerous other changes take place through the outgrowth 

 of various "prongs" and other structures, through the modification of the 

 tergites, such as the posterior prolongations of the lateral region of the ninth 

 tergite labeled "i" in Fig. 6, etc., but these features have been more fully de- 

 scribed in an artiek' which will soon ajipear in Psyche, and need not l)e further 

 discussed here. 



Abbreviations. 



?. Styligers or "coxites"; basal structures bearing the styli. They may 

 unite to^form a single plate or basal ring. 



b. Basal segments of the styli or gonopods. 



c. Distal segments of the st>li or gonopods. 



d. Penisvalva" or vaKes of the "penis." 



e. Paraprocts, or plates on either side of the anus. 



f. Cerci. 



g. Telohlum, or terminal filament. 



h. Proctiger, or anal papilla bearing anus. 



i. Surgonopods, or accessory elaspers; prolongations of the ninth tergite. 



The ninth sternite "9''" forms the hypandrium, the ninth pleurite "O""' 

 forms the gonopleurite, and the tenth or eleventh tergite forms the epiproct- 

 The letters t, p and s written to the right aufl above the numerals are used to 

 indicate the tergite, pleurite and sternite of their respecti\'e segments. 



Explanation of Plate VI. 



Fig. 1. Lateral view of terminal structures of a blattid (based on 



Cryptocercus) . 

 Fif. 2. \'entral view of genital forceps of a sawfly (based on Sircx). 

 Fig. 3. Lateral \iew of terminal structures of a eawfly. 

 Fig. 4. \'entral view of genital forceps of a mayfly (based on Blasl-iirus). 

 Fig. 5. Lateral view of terminal structures of a mayfly. 

 Fig. 9. Lateral view of terminal structures of a Neuroptercn (based on 



Nymphes and Ithoric). 

 All figures are very diagrammatic. 



