164 Proceedings of the Royal Physical Society. 
accessory gland (anhangsdruse), but it must be considered part of the 
receptaculum proper, for it proved on examination to be filled with sperms. 
It is most probably an accessory sac or reservoir. 
Just below the bursa copulatrix is the vagina, surrounded by a band of 
chitin which binds the spiculum ventrale to it. It is further protected by 
two pore-bearing plates of chitin, ending in two papille, probably of use in 
oviposition, 
The accessory organs of reproduction or genitalia of the female, as already 
mentioned, comprise the seventh and eighth terga, the eighth sternum, the 
spiculum ventrale, and the vaginal plates and palpi described above. 
The eighth tergum (Fig. 3) is smaller than the seventh, which completely 
covers it. It bears numerous sense bristles. The seventh tergum is a- 
broader plate. At its anterior end, where it adjoins the sixth, three semi- 
circular areas occur showing finer spinule than the rest of the segment. 
The eighth sternum (Fig. 4) is a stout, broad plate, the edges of which are 
folded inwards a little. 
The spiculum ventrale (Fig. 5) is a rod-shaped structure forking posteriorly 
into two lobes which are slightly thinner than the rod, and bear a number of 
stout bristles. It is attached to the eighth sternum by a web-like band of 
chitin. 
THE MALE REPRODUCTIVE ORGANS. 
These comprise the testes, the paired vasa deferentia with their sperm sacs 
and diverticula, the unpaired vas deferens, and the penis (Fig. 6). 
The testes may be said to be four in number lying in pairs on either side 
of the median line. Viewed ventrally they appear as flat discs, laterally they 
appear double convex. Each disc appears to be made up of a number of 
seoments. From the centre of each disc a short tube arises. These unite to 
form the paired vasa deferentia, which themselves unite to form the unpaired 
vas leading to the penis. 
Midway between the testes and the unpaired vas, a short tube opens 
from the paired vasa and immediately branches into two long diverticula. 
Just below these short tubes the bulb-shaped sperm sacs lie. - 
The unpaired vas deferens is formed by the junction of the paired vasa, 
and for about a third of its length is of the same size. It then tapers 
suddenly, and, enclosed in chitin and exterior to that with muscle, winds 
in a zig-zag manner till it reaches the bulb of the penis, The bulb is 
considerably dilated and tapers halfway as the ejaculatory duct. 
The male genitalia comprise the seventh and eighth terga, the eighth 
sternum, two chitinous sternal plates, and the fork or false spiculum 
gastrale (representing the ninth sternum), the ring and the sheath. 
