36 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. IO3 



convergent beneath the first, and inserted in the apical notch of the 

 foramen (B, 41). The third pair of levators are large three-branched 

 muscles arising by broad bases on the episterna (D, 43), one branch 

 of each muscle (42(1) above the horizontal apodeme of the episternum 

 (c), the second (^-'b) on the side below the apodeme, the third (4^c) 

 on the ventral expansion ; the three branches converge to a strong 

 tendon attached in the laterodorsal notch of the foramen (B, 42a, 



4-0 41 



Fig. 12. — Muscles of prothorax (drone). 



A, dorsal muscles, ventral view. B, ventral and lateral muscles, dorsal view. 

 C, muscles of endosternum and fore coxae, posterior view. D, branches of 

 cephalic muscle 42 arising on inner face of proepisternum. 



c, horizontal apodeme of episternum; d, cervical apodeme of episternum; 

 e, occipital process of episternum; m, supraneural bridge of endosternum. 



only one branch, on the left side, shown in this figure). The fourth 

 pair of head levators arises posteriorly on the dorsal surface of the 

 supraneural bridge of the endosternum (B, C, 4^), the fibers of each 

 muscle converging to a long, thick tendon attached on the head just 

 laterad of the pleural levator (B, 4^). The depressors of the head 

 are a pair of large two-branched muscles (B, 44,) arising on the 



