NO. 8 



INSECT ABDOMEN— SNODGRASS 



113 



from the other segments, however, it is seen to consist of a long oval 

 lobe on each side (B, I XT) having the usual relations with the 

 valvifers of the ovipositor {iVlf, 2Vlf) ; its dorsal part forms a 

 narrow median bridge between the lateral lobes, with which is 

 ankylosed the dorsal plate of the proctiger {Ptgr). 



The ovipositor of Megarhyssa is in no way different structurally 

 from that of a braconid. The first valvifer (fig. 37 B, C, D, iVlf) 



Fig. 37.— End of abdomen and structure of ovipositor of Megarhyssa atrata 

 ( Ichneumonidae ) . 



A, end of abdomen and basal parts of ovipositor. 



B, ninth segment and proctiger with basal parts of ovipositor. 



C, base of ovipositor, left side. 



D, first valvifer and proximal end of first valvula. 



E, second valvifer, w^ith proximal parts of second and third valvulae attached. 



F, distal end of shaft of ovipositor. 



is a small oval plate articulating dorsally with the ninth tergum 

 (B, a), and ventrally with the second valvifer (C, b). The first 

 valvula arises from its dorsal end (D, c) and curves downward 

 and posteriorly around the lower end of the second valvifer. Each 

 first valvula has a slender but conspicuous basal branch (B, D, v). 

 The second valvifer is an elongate plate (C, E, sVlf) with its an- 

 terior end produced upward in a hook-shaped lobe, to which the 

 first valvula {iVl) is attached; distally it bears the long, slender 



