1918] Crampton — Genitalia of Male Neuroptera, etc. 53 



jointed forceps-like structures as in the Panorpa-group (Figs. 

 24, 23, etc.), and since the Biftacus-group seems to be as primitive 

 as any, so far as the terminal structures and genitalia are concerned, 

 I have used them as the basis for a comparison with the other 

 Mecoptera and the Neuroptera. Bittacus (Figs. 18 and 22) seems 

 to resemble Nymphes (Fig. 3) as much as any Neuroptera, in 

 respect to its terminal structures; and the median terminal ap- 

 pendage "sa" of Figs. 18 and 22, which is either homologous with 

 the supraanal plate (epiproct) or with the anal tubercle (proctiger), 

 is apparently the homologue of the median terminal structure 

 labeled "sa" in Fig. 3 of Nymphes. The copulatory claspers 

 "cl" of Bittacus (Figs. 18 and 22) are possibly represented by the 

 lobes labeled "cl.'" in Fig. 3 of Nymphes, and are analogous to, if 

 not actually homologous with, the copulatory claspers, "cl," of 

 the Phasmid shown in Fig. 9, and doubtless had a similar origin. 

 The claspers "cl" are very large in Bittacus strigosus (Fig. 18); 

 but are much smaller in Bittacus pilicornis (Fig. 22). Correlated 

 with the greater development of the claspers "cl" of Bittacus 

 strigosus (Fig. 18), there is a greater development of the appendages 

 labeled "c" (which are provisionally homologized with the cerci) 

 than in Bittacus pilicornis (Fig. 22), although in the latter insect, 

 the median appendage "sa" is proportionately somewhat larger 

 than that of B. strigosus (Fig. 18). In both insects shown in Figs. 

 18 and 22, there occurs a pair of closely approximated hooks la- 

 beled "pu," provisionally homologized with the penis hooks. 

 Between them there projects a spiral thread or spirofilum "sf," 

 wound like a watch spring. It is possible that this spiral thread 

 represents the columna "co" of Fig. 10. At the base of the hooks 

 "pu" (Figs. 18 and 22) is a pair of appendages labeled "g.^" 

 which may represent the gonopods of the other Mecoptera, al- 

 though I would not insist upon this interpretation. Miyake, 

 1913, on the other hand, regards the hooks "pu" (Figs. 18 and 22) 

 as parts of the *' pedes geni tales." 



In comparing the Panorpa-group with the Bittacus -type, one 

 of the most noticeable features is the lack of development of the 

 claspers "cl" in the former group. On the other hand, the gono- 

 pods "g" are greatly developed in the Pmiorpa-group (Figs. 24 

 20, 23, and 27). I am not sure that the distal segment of the 

 gonopod "g" of Fig. 23 is homologous with the appendage labeled 



