140 Dr. G. C. Craniptnn on the Primitive 



ierm.es : " Al)dominis sterniiiii septiiiinm in parte postica 

 mediaiia angustatum, productiim, margine postico sinuato, 

 sternum octavum et nonum nondiim obtegens. Sternum 

 octavum appendicibus genitalibus duabus brcvibus ; ster- 

 num nonum stilis instructum." Since the abdomen of 

 females of the soldier caste is similar to that of the worker 

 caste, the above-cited description applies equally well to 

 the female soldier depicted in text-figure 1 of the present 

 paper, since in the figure in question the seventh abdominal 

 sternite is narrowed posteriorly in the median region, it 

 is somewhat produced, its posterior margin is siimate, 

 and it projects slightly over the eighth and ninth sternites. 

 The eighth sternite likewise bears two " genital appendages " 

 (labelled " vv " in text-figure 1), and the ninth sternite 

 bears a pair of styli " s." I find in addition, however, 

 a third pair of appendages labelled " iv," which are very 

 small, and on this account apparently escaped Silvestri's 

 attention, although they occur in the females of both soldiers 

 and workers. The intermediate appendages, labelled 

 " iv " in text-figure 1, occur between the bases of the styli, 

 labelled " sg." There is some indication that they may 

 possibly belong to the sternite behind the ninth {i. e. the 

 partially atrophied tenth sternite) which would be in agree- 

 ment with the claim made by Dr. Wheeler, that the inter- 

 mediate valves of the ovipositor belong to the tenth segment 

 of the embryo (and come to have their position between 

 the dorsal valvulae of the adult as a later modification), 

 but my material was too poorly preserved definitely to 

 determine this point. 



Dr. Walker (Canadian Entomologist, vol. li, 1919, pp. 

 131-139), following Wood-Mason, Handhrsch, Berlese, 

 and others, would interpret the dorsal valves of the ovi- 

 positor of Orthopteroid insects as representing the styli 

 together with their basal portions " sg " (text-figure 1), 

 from his studies on Gryllohlnita ; and the condition exhibited 

 by the females of the worker and soldier castes of Masto- 

 termes would uphold this view, for it is quite evident that 

 the ventral appendages labelled " vv " in text-figure 1, 

 represent the ventral valves of a primitive ovipositor, 

 while the appendages labelled " iv " represent the inter- 

 mediate valves, and the styli " s," with their basal portions 

 " sg," apparently enter into the composition of the dorsal 

 valves of the ovipositor of the Orthopteroid forms (see 

 also figures of " Blatta,'" by Wood-Mason). The presence 



