364 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 1 37 



EXPLANATION OF PLATE 



Plate i 



Musculature of mesothorax of Diptera. 



a, Anisopus. Transverse slice of mesothorax containing the furca, muscles 

 related thereto, and other muscles of leg base; indirect flight muscles removed, 



b, Sciara. Dissection of half animal with indirect flight muscles removed and 

 showing long, thin, tergal depressor of trochanter muscle; pleural and leg- 

 base musculature can be seen. 



c, Tipulid. Dissection of half animal with indirect flight muscles removed. 

 No tergal depressor of the trochanter muscle. Among the pleural muscles can 

 be seen well-developed coxosubalar muscle. 



d, Musca. Dissection of half animal with longitudinal indirect flight muscles 

 and some of dorsoventral indirect flight muscles removed to show well-devel- 

 oped tergal depressor of trochanter muscle. 



e, Calliphora. Animal cut transversely and indirect flight muscles removed to 

 show position and shape of tergal depressor of trochanter muscles. 



/, Glossina. Transverse slice of mesothorax showing furca and muscles re- 

 lated thereto ; indirect flight muscles removed. 



(Photographs by the author.) 



