Fig. i6. — Dissection of the pterothorax (drone). 



A, mesothorax and wing bases, dorsal view, with most of scutal area removed exposing 

 ends of longitudinal and dorsoventral muscles. B, major scutal plate of mesothoracic notum, 

 ventral view. C, pterothorax with pleural and propodeal walls removed on left side, showmg 

 phragmata and muscles. D, posterior notal plate of mesothorax and attached second phragma, 

 ventral view. E, metanotum, dorsal view. F, ventral surface of thorax, legs and propectus 

 removed. G, left lateral arm of mesoscutellum and corresponding stalk of second phragma, 

 lateral view. H, ventral half of pterothorax, dorsal view, showing endoskeletal structures. 



f, posterior marginal ridge of mesopleuron; i, conjunctiva between mesopleuron and meta- 

 pleuron; k, anterior inflection of metapleuron; m, groove between metapleuron and propodeum; 

 n line of external groove n (fig. 15); ns, notal sulcus; 0, ridge of external groove m (fig. 15): 

 p, process of mesosternal ridge giving attachment to muscle 5« (fig- 22t ) ; q, process of supra- 

 neural bridge of endosternum giving attachment to muscle 52 (fig. 22C); r, lobe of ridge o 

 giving attachment to basalar muscle of metathorax (fig. 21H, loi)\ s, median ridge ot 

 metasternum; sf, scutal fissure; t, median process of propodeum giving attachment to 

 muscles g6 {C, and fig. 27C); m, v. outer and inner lamellae of basal stalk of second phragma; 

 w. articular process on stalk of second phragma for axillary lever. 



(44) 



