22 



Studies in the Hybrid Bistoninae. IV 



doptera, is obscure and, therefore, exceedingly difficult to make out, is 

 here much simplified. 



At the end of the abdomen may be seen the bristle-tipped ovipositor 

 lobes to which are attached a pair of stout black rods called the inner 

 directing rods, the function of which is to secure the insertion of the 

 ovipositor in nooks and crannies suitable for the reception of the ova. 

 This portion represents the female 10th abdominal segment. Anterior 

 to this part is another section likewise armed with a pair of directing 

 rods ; this is all the female has in the way of a 9th segment. 



Segment 10 with inner 

 directing rods 



Segment 9 with outer 

 rods 



Ostium 



Ductus bursae 



Signum 

 Bursa copulatrix 



Segment 8 

 Segment 7 



Segment 6 



Segment 2 



-Segment 1 

 Fig. 2. Female genitalia of L. hyb. hulli. 



In most Lepidopterous females the 8th segment appears to be obsolete. 

 In this sub-family it presents a more or less distinct tubular or collar-like 

 structure bearing anteriorly the orifice of the female genital pouch. To 

 this opening the name Ostium bursae, or simply Ostium, is applied ; in 

 the Bistoninae, it is armed with a thin chitinous plate or guard flap. 

 Leading to the Bursa copulatrix proper from the ostium is a narrow 

 tube, the Ductus bursae, from which issues the Ductus seminalis. The 



