1868.] 



397 



[Packard. 



Fig. 8. 



In the pupa (Tigs. 8, 8a, enlarged) of another species of jEschna, 

 though of the same age as the othei-, the wing-pads being of the same 

 size, the male genitals can be seen. Thci-e are no ap- 

 pearances of any tubercle, or any marking whatever, 

 indicating their presence on the eighth ring, but on 

 the ninth there are two pairs of flattened tubercles; 

 the inner pair being regular oblong-oval, the outer 

 orbicular, and much larger. These ai-e to form the 

 male intromittent organs, so considered by Burmeis- 

 ter, while the organs at the base of the abdomen are, 

 rrjT^ as stated by authors, probably organs of excitement. 



In the larva of Agrion the ovipositor (Fig. 9, front 

 Fig. 8, a. j^jjj g^jjg view; 8, 9, 10, 11 represent the four 



terminal segments of the abdomen; d one of the three false gills, e a 

 supplementary style) is nearly identical with that of the larva and 

 semi-pupa of Bomhus. As seen in the figure, 

 the rhabdites are large and blade-like. The 

 ovipositor is so far developed that the origin 

 of the first pair (a) is seen to be just under 

 the posterior end of the eighth urite, and by 

 analogy it seems right to assume that, in an 

 earlier condition of the insect, it arises from 

 the surface of the eighth urite, as we have 

 seen above in the Bonibus larva. Seen side- 

 ways, the first pair of rhabdites are laid be- 

 tween the outer pair (e) of the succeeding 

 urite, and do not ensheath them as in Bomhus. 

 In jEschna (as in Bomhus), the first rhab- 

 dites ensheath the two other pairs; and in 

 the pupa of Agrion this may be the case. 



The accompanying figure (10), reduced from a drawing of Lacaze- 

 Duthiers, gives a theoretical section of the abdomen, showing the 



relative position of the 

 outlet of the alimentary 

 canal (r) and the ovi- 

 duct (o), in relation to 

 the ovipositor, a repre- 

 sents the "lateral scale," 

 or one half of the outer 

 sheath, and a' its valv- 

 ular part; e the support 

 whh 



Fig. 9. 



Fig. 10. 



of the stylets, or second pair of rhabdites (i); and /the stinj 

 t/, its support. 



We do not here attempt to study the structure of the ovipositor in 



