340 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I37 



C. DORSOVENTRAL MUSCLES. 



4. TERGOSTERNOPLEURAL (INDIRECT FLIGHT) MUSCLE (fIG. 3). 



Other names are: Tergosternal muscle (Snodgrass), ist dorso- 

 ventral muscle (Ritter), anterior tergosternal muscle (Maki), ist 

 dorso ventral muscle (Bonhag), tergosternal muscles (Miller in 

 Demerec). 



Fig. 3. — Anisopns jcnestralis Scop., right half of mesothorax with dorsal 

 longitudinal (indirect flight) muscles removed to show dorsoventral (indirect 

 flight) muscles beneath and oblique dorsal muscle beneath. X 42. 



This large muscle runs from the tergum to the so-called sterno- 

 pleuron. It is of the giant-fiber type and, in Anisopus, comprises from 

 seven to nine giant fibers. The muscle lies external to the dorsal 

 longitudinal (indirect flight) muscles and anterior to the muscle that 

 connects the pleural wall to the furca (D, ii). The number of 

 fibers may vary on either side of a specimen. It acts as an indirect 

 elevator of the wing. 



