NO. 2 THORACIC MUSCLES OF THE COCKROACH — CARBONELL 17 



156. Third dorsal oblique muscle (fig. 37). — Very short muscle. 

 Origin on the tergum, insertion on an upward-bent flange on 

 the lateral part of the edge of the first abdominal tergum. 



757. Tergo-pleural muscle (figs. 37, 38, 39). — Broad, powerful mus- 

 cle; origin on lateral part of the tergum, goes downward and 

 outward to its insertion on the upper surface of the pleural ridge. 



1^8. Pleuro-cdar muscle, flexor of the wing (figs. 37 to 42, 44). — 

 Arises from the under surface of the pleural ridge, goes upward 

 to its insertion on the third axillary (fig. 36, 3 Ax). 



159. Tergo-pleural muscle (figs. 37 to 43). — Broad, flat bundle of 

 short fibers going from a broad origin on the anterior edge 

 of the pleural arm to its insertion on a downward-bent part of 

 the anterior notal wing process which articulates with the first 

 axillary {lAx in fig. 36). 



160. Pleuro-sternal muscle (figs. 40 to 43). — Broad, flat, short mus- 

 cle going from the anterior edge of the pleural arm to the an- 

 terior edge of the sternal arm, 



161. First tergal muscle of the trochantin (figs. 37 to 46). — From 

 a broad insertion on the anterior edge of the tergum goes taper- 

 ing backward and downward to its insertion on the surface of 

 the posterior end of the first plate of the trochantin {iTn in 



fig. 50)- 



162. Second tergal muscle of the trochantin (figs. 37 to 46). — Origin 

 on the anterior edge of the tergum, mesal of 161; goes in the 

 same direction as 161 to its insertion on apodemal tendon of the 

 mesal edge of the first plate of trochantin. 



163. Third tergal muscle of the trochantin (figs. 37 to 46). — Origin 

 on anterior portion of the tergum, goes in the same direction as 

 162 to the same apodemal tendon. 



164. First episternal muscle of the trochantin (fig. 47). — Broad, flat 

 muscle. Origin near anterior edge of the episternum, goes ven- 

 trally to its insertion on the surface of the first plate of 

 trochantin. 



idf. Second episternal muscle of the trochantin (figs, 47, 48). — Flat 

 bundle of fibers which has its origin near the anterior edge of 

 the episternum and goes ventrally to a broad insertion on the 

 anterior edge of the first plate of the trochantin. 



166. Third episternal muscle of the trochantin (figs. 48, 49). — Flat, 

 short, fan-shaped muscle arising from the surface of the epi- 

 sternum, inserts on the anterior edge of the first plate of the 

 trochantin, lateral of the insertion of 16^. 



