250 



MR. B. F. CUMMTNGS ON 



diverticulum gives off a posterior root. On the sixth there is also 

 an anterior root. In segment 2, where there are no spiracles, a 

 diverticulum nevertheless exists and runs out on each side as a 

 small twig. 



Text-figure 3. 



Polyplax brachyrrhyncJms. Male copulatory apparatus. X 433. 



HP. B,asal pl^te. Par. Paraaieron. P. Penis. Ma. Mesqsqme (anterior piece). 

 Mjo. Mesosome (posterior piece). 



The coulee of the tracheals in head and -thorax was too un- 

 certain to justify description. 



