NO. 2 THORACIC MUSCLES OF THE COCKROACH — CARBONELL 9 



5d. Episternal muscle of the head (figs. i8, 19, 20). — Arising from 

 the anterior external angle of episternum, inserted dorsally on 

 postoccipital ridge of the head. 



5y, 58. Cephalic muscles of the cervical sclerites (figs. 19, 20). — 

 Origins on dorsal part of postoccipital ridge, external to 56 ; 

 both extend laterally and posteriorly, ^y inserted on the first ven- 

 tral cervical sclerite, ^8 on the second. 



Sp. Prothoracic longitudinal dorsal muscle (figs. 3, 18). — A flat mus- 

 cle extending from the median portion of the first phragma to 

 the integument of the neck in the point where it bends upward 

 to join the pronotum. 



60. Oblique dorsal muscle (figs, i, 19). — Broad, flat, fan-shaped 

 muscle. Its several bundles of fibers arise dorsally from the 

 median part of the pronotum and converge to their insertion on 

 a small, anvil-shaped sclerite firmly attached to the lateral portion 

 of the first phragma, very close to the base of the fore wing. 



61. Oblique dorsal muscle (figs, i, 2, 19). — Same form as 60 but 

 considerably smaller, lies partially underneath it, and its fibers 

 arising from the median line of pronotum converge to their in- 

 sertion on the same sclerite. 



62. Transverse dorsal muscle (fig. 2). — From the medial portion of 

 the phragma to the same insertion as 60 and 61. 



6j, 64. First and second protergal muscles of the first cervical 

 sclerite (figs, i, 2, 3, 18). — Origins on the anterior edge of the 

 protergum, descending vertically to insertions on the first ven- 

 tral cervical sclerite. 64 is twisted around dj. 



65, 66. First and second protergal muscles of the pleural arm (figs. 

 2, 3, 4, 5, 6, 8, 9, 10). — From the protergum to the end of the 

 pleural arm. Both short, small muscles arising from different 

 parts of the protergum and converging to their insertion on the 

 end of the pleural arm at its articulation with the sternal arm. 



d/. Third protergal muscle of the pleural arm (figs. 3, 5, 6, 7, 8, 9, 

 10, 11). — Origin on anterior edge of the protergum, goes ob- 

 liquely downward and backward to the upper surface of the 

 pleural arm. 



68. Fourth protergal muscle of the pleural arm, (figs, i, 2, 3, 4, 5, 6, 

 8, 9, 10, II, 12). — Origin near the anterior margin of protergum, 

 goes downward and backward to the under surface of the pleural 

 arm, 



dp. Protergal muscle of the neck (figs. 3, 5, 6, 8, 19, 20). — Arises 

 from the anterior part of the protergum and goes downward to 

 its insertion on a fold of the ventral integument of the neck. 



