12 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. IO7 



Numbers po to p^ have been left for the muscles of the rest of the 



fore leg. 



p6. Phragmal muscle of the sternal arm (figs. 17, 54). — Slender 

 muscle from the lateral portion of the first phragma to the sternal 

 arm. 



py. Episternal muscle of the coxa (figs. 5, 6, 54; in figs. 5 and 6 it is 

 cut). — Flat, ribbonlike muscle, arises from the internal edge of 

 the mesepisternum, goes to prothoracic coxa on opposite side, 

 where it inserts on a ridge that begins at coxo-pleural articula- 

 tion. Its fibers divide into two or more bundles in the midline of 

 the body, where they cross with those of the corresponding mus- 

 cle from the opposite side. Acts probably as a rotator. 



p8. Spinal muscle of the coxa (figs. 5, 6, 54; in figs. 5 and 6 it is 

 cut). — Flat muscle, arises from first spina, inserts on the same 

 ridge as p/. Acts probably as a rotator. 



pp. Sterno-spinal muscle (fig. 54). — From sternal arm to first spina. 

 The following muscles {100 to 106) are intersegmental. 



100. Ventral longitudinal muscle (fig. 54). — Extends between pro- 

 thoracic and mesothoracic sternal arms. 



10 1. Sternal-spinal intersegmental muscle (fig. 54). — From sternal 

 arm of the prothorax to second spina. 



102. Ventral oblique muscle (fig. 54). — Slender muscle, extends 

 from prothoracic sternal arm to the edge of mesepisternum of 

 the opposite side. 



70J. Transverse ventral muscle (fig. 54). — Broad, flat, short bundle 

 of fibers from the first spina to the medial edge of the mes- 

 episternum. 



104. Spino-sternal muscle (fig. 54). — From first spina to base of 

 mesothoracic sternal arm. 



103. Spinal rotator of the mid-coxa (fig. 54). — Long, flat, slender 

 muscle arising from first spina, inserted on the ridge which 

 limits the meron of the mid-coxa. 



106. Spinal longitudinal ventral muscle (fig. 54). — Very slender, 

 threadlike muscle, going along the median line from the first to 

 the second spina. 



MESOTHORAX 



10/. Closing muscle of the first spiracle (fig. 35). — Small flat, tri- 

 angular muscle arising from the anterior part of the chitinous 

 ring that surrounds the spiracle, going upward to its insertion 

 on the median part of the anterior lip. 



