no SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. ©9 



larva and the embryo are those of the tenth segment. Hence, it seems 

 probable that the proctiger of adult Lepidoptera and Hymenoptera is 

 mostly the tenth segment of the abdomen, and that its appendicular 

 processes, if they represent segmental appendages at all, are the 

 appendages of the tenth segment. Likewise the processes of the 

 proctiger in adult male Trichoptera appear to be homologues of the 

 socii of Lepidoptera, and here again the terminal appendages of the 

 larva belong to the tenth abdominal segment. The writer, therefore, 

 tentatively designates the appendages of the proctiger in Trichoptera, 

 Lepidoptera, and Hymenoptera the socii, since clearly it is more 

 probable that they represent the pygopods, or appendages of the tenth 

 segment, present in the larvae, than that they are the cerci, or append- 

 ages of the eleventh segment, which segment is suppressed in the 

 larvae of all these insects. 



On the other hand, the terminal appendicular processes of the ab- 

 domen of adult Mecoptera and Diptera may be true cerci. In Panorpa 

 they arise from a small but distinct end piece of the abdomen beyond 

 the tenth segment, which bears the anus on its ventral surface, and is 

 therefore the eleventh segment. The morphology of the terminal 

 appendages of Mecoptera and Diptera is discussed in a recent paper by 

 Gerry (1932), who regards the structures as cerci. 



ATANYCOLUS RUGOSIVENTRIS (aSHMEAd) 



The ovipositor of this member of the Braconidae will illustrate 

 the structure of the slender, elongate type of ovipositor characteristic 

 of many of the parasitic Hymenoptera. The functional abdomen of 

 a braconid, as that of all the higher families of the order, contains 

 only nine segments, since the first abdominal segment forms the pro- 

 podeum of the thorax, and there is but one postgenital segment, which 

 is the proctiger. 



The abdomen of Atanycolus rugosiventris (fig. 36 A) is elongate 

 oval, rather broad, and of a pale orange color contrasting with the 

 blackish thorax, head, and legs, and the dusky wings. The terga and 

 sterna of the visceral region are separated by wide lateral membranous 

 areas, and the tergal plates of segments HI and IV are fused. The 

 slender shaft of the ovipositor (Ovp) is nearly as long as the abdomen 

 and thorax, and the third valvulae {3 VI) are correspondingly length- 

 ened and narrow. In life the third valvulae probably ensheath the 

 ovipositor between their hollowed inner surfaces. The seventh, eighth, 

 and ninth tergal plates of the abdomen are narrowed above (B) and 

 separated by wide intersegmental membranes. The seventh sternum 

 (VIIS) projects posteriorly beneath the base of the ovipositor as a 



