132 



Annals of the South African Museum. 



of the posterior sternal sigilla " (Ann. Durb. Mus. vol. i, pt, 3, p. 233). 

 Fig. 13 shows the characters under considei'ation, and though no 

 doubt the one form can be considered as arising from the other by 

 a muscular alteration and migration as in Gorgyrella, the difference 

 thus brought about is surely generic. No doubt, as Hewitt says, 

 the characters by which Simon separates the Cyrtaucheniese from the 

 Nemesieae are not very clear and definite ; and further knowledge will 

 perhaps bring about rearrangements there and elsewhere. Never- 



B 



B D 



FIG. 13. Homostola zebrina. B. Sp/roctenus validus. C. Spiroctenus 

 schreineri. D. Stictogaster reticulatus. 



theless, though Homostola should preferably be in the same group as 

 Spiroctemia, the two seem geuerically separate. Stictogaster (Text- 

 fig. 13 D), contains but the one species on which the genus was 

 founded, and is allied to, but distinct from, Spiroctenus; further 

 material and the discovery of the <$ of the specimens is necessary 

 to decide whether the generic characters are constant and valid ; in 

 the meantime, there is no advantage in calling it Spiroctenus. 

 Hewitt apparently considers that as extreme members of one genus 

 may resemble the opposite extreme members of another genus, that 



