NO. 2 THORACIC MUSCLES OF THE COCKROACH — CARBONELL II 



83. Sternal muscle of the coxa (figs. 8, 9, 10, 11). — Arises on the 

 sternal arm, goes to the basicosta of the coxa. Acts probably as 

 a remotor. 



84. Prosternal muscle of the cervical sclerite (figs. 17, 54)- — A slen- 

 der muscle, going horizontally from its origin on the sternal arm 

 to the second cervical sclerite (figs. 15, 61, 2Cv). 



85. Main depressor of the leg (figs, i to 12). — It is the most power- 

 ful muscle in the fore leg and prothorax. From several origins on 

 different parts of the prothorax and coxa, its branches converge to 

 a broad apodemal tendon arising from the proximal angle of the 

 trochanter. Its branches are: 



a. First tergal branch (figs, i to 10). — Origin on the anterior 

 edge of the protergum. 



b. Second tergal branch (figs, i to 10). — Origin on the tergum, 

 posterior to branch a. 



c. Pleural branch (fig. ii). — Its origin covers partly the pos- 

 terior edge of the pleural arm and advances over part of the 

 upper surface of the pleural ridge and the epimeron. 



d. Pleural branch (fig. 12). — Origin on the under surface of the 

 pleural arm and pleural ridge. 



e. First coxal branch (fig. 8). — Origin on the medial portion of 

 the wall of the coxa. 



/. Second coxal branch (figs. 8, 9). — Origin on the posterior 

 (dorsal) wall of the coxa. 



g. Third -coxal branch (fig. 13). — Origin on the anterior (ven- 

 tral) wall of coxa and basicosta of the coxa. 



h. Fourth coxal branch (figs. 9, 10, 11, 12). — Arises from the 

 medial portion of the wall of coxa. 



86. Posterior depressor of the leg (fig. 7). — Origin on the posterior 

 (dorsal) wall of coxa, goes to apodemal tendon on the trochanter. 



8^. Anterior depressor of the leg (figs. 13, 14). — Origin on the inner 

 portion of the anterior (ventral) wall of the coxa, goes to apode- 

 mal tendon of trochanter. 



88. Main levator of leg (figs. 7 to 14). — Two branches converge on 

 a common apodemal tendon on the trochanter. . 



a. Anterior branch (figs. 7 to 14). — Arises from anterior (ven- 

 tral) wall of coxa. 



b. Posterior branch (figs. 7 to 13). — Arises from posterior 

 (dorsal) wall of coxa. 



8p. Secondary levator of the leg (fig. 7). — Small, weak muscle aris- 

 ing from posterior (dorsal) wall of the coxa, goes to apodemal 

 tendon of trochanter (tendon shown in figs. 8 to 13). 



