NO. 3 



INSECT HEAD SNODGRASS 



119 



50> 5^- — Cephalic muscles of the cervical plates (fig. 45 A, B). 



Origin on postoccipital ridge below 4p; both extend ventrally and 

 posteriorly, the first (30) inserted on first cervical plate, the second 

 (57) on second plate. 



5^. 53-—Protergal muscles of the cervical plates (fig. 45 B).— 

 Origin dorso-laterally on prothoracic tergum; both extend ventrally 

 and anteriorly, crossing internal to 50 and 51, to be inserted on first 



Fig. 45. — Muscles of the neck of Dissosfeira Carolina, right side, internal 

 view. 



A, muscles extending between head and prothorax, omitting 52, 5-3 and 54, 

 inserted on cervical sclerites (B). B, head and prothoracic muscles of cervical 

 sclerites. 



Bsi, basisternum of prothorax; c, first ridge of protergum; icv, first cervical 

 plate ; ^cv, second cervical plate ; d, second ridge of protergum ; e, third ridge 

 of protergum; Epsi, episternum of prothorax; EpS2, episternum of mesothorax ; 

 g, process of head articulating with first cervical sclerite; H, head; iPIi, first 

 thoracic phragma; PoR, postoccipital ridge; FT, base of posterior arm of 

 tentorium ; Rd, posterior fold of protergum ; SA, apophysis of prothoracic 

 sternum ; Spn, spina ; Ti, tergum of prothorax. 



cervical plate, the first {32b) with a branch {32a) to articular process 

 (g) oi postoccipital ridge. 



34. — Prosternal muscle of the first cervical plate (fig. 45 A, B). — A 

 diagonal, horizontal muscle arising on apophysis of prothoracic ster- 

 num (A, SA), crossing its fellow to insertion on inner edge of first 

 cervical plate of opposite side (B). 



33. — Longitudinal ventral muscle of the prothorax (fig. 45 A). — A 

 broad, flat muscle from prosternal apophysis (SA) to base of poste- 

 rior arm of tentorium (PT). 



