618 



MAHGAllET ROBINSON. 



There were no adult Archispirosfcreptus at my disposal, 

 I have therefore made use of some adult Spirostreptus 

 collected by Professor Minchin in Uganda. 



In the adult Spirostreptus there is behind the hypo- 



Text-fig. 1. 



^ cly 



Ant. 



md.— > 



Diagrammatic plan of the mouth-parts of the larva of Archispirostreptus 

 five days after it leaves the egg-shell. 



stome a piece of chitin, which, though larger than the hypo- 

 stome, resembles it in shape (text-fig. 5). The simplest way 

 of accounting for this would be to consider it as representing 

 the sternum of the post-maxillary segment. The tergum of 



Tbxt-fig. 2. 



Ant. 



......Q(^_^^:^-_^Q 



T- - -ClIJ. 



-/ m X. 



Mouth-parts of larva ten days after leaving the shell. 



this segment is exceptionally large, and seems to represent 

 two tcrga, namely, that of the post-maxillary segment and 

 that of the first leg-bearing segment. The segment follow- 

 ing that which bears the third pair of legs (fifth body segment) 

 is apodous in Spirostreptus. 



Heathcote (1888) in his account of the development of 



