2e 



Studies in the Hybrid Bistpninae. IV 



Proceeding from the uncus base and merging insensibly into the first 

 pair of directing rods is a thin chitinous structure evidently the upper 

 lateral portion of the tegumen. Once more we gain proof of the 

 homology of the saccus, and the ventral parts of the tegumen, with the 

 directing rods. Next, as in the first insect, are the two valves distorted, 

 it is true, to a slight extent but approximating more closely to the 

 normal form. Between them, and lying to the right, is the aedoeagus, 

 the vesica of which is ornamented as usual with cornuti but with this 

 anomaly that they are here duplicated. 



The lower pair of rods call for no particular comment ; nor is there 

 much reason for specially noting the 8th female abdominal segment. 

 Again, however, this segment is doubled by the advent of a second 

 segment possessing the characteristics of the same segment of the male. 

 The extra segment is not so perfect as in the last instance and appears 

 as an irregular chitinous ring at R. Nor is the ostium bursae so plain 

 but it is to be found on the right just above the lower rods. In this 

 insect, the ductus bursae is shorter and the bursa copulatrix itself more 

 globular. On its inner surface is the somewhat larger signum, the 

 spines of which are thicker and stronger than in the last specimen. 



(3) Wing parts, PI. I, Fig. 4. Genitalia, Text-fig. 5. 



Fig. 5. 

 : Bursa copulatrix. DD= 1st pair of rods. D'Z)' = 2nd pair of rods, 



i^— Fragment of duplicated 8th segment. = Ostium. <S= Signum. 

 F= Valve. Fe=: Vesica. Z7= Uncus. 



