NO, 7 MUSCULATURE OF COLEOPTERA — DORSEY 5 



9. Dorsal dilator muscle of the anterior, region of the pharynx 

 (figs. I, 2). — Arises on the frons anterior to muscle ii and is inserted 

 on the dorsal wall of the pharynx immediately behind the frontal 

 ganglion connective, 



10. Muscle of hypo pharyngeal bar Y (figs, i, 2), — A branched 

 muscle : branch a arises on the frons immediately laterad of muscle 11 

 (fig. i) ; branch b arises laterally in the anterior region of the frons. 

 Both branches are inserted on the dorsal end of the sclerotized bar Y 

 (fig. i), branch b laterally. 



11. Dorsal dilator muscle of the pharynx (figs. 1,2) . — Arises on the 

 frons immediately laterad of the dorsal muscle of the labrum, 4, and 

 is inserted slightly laterally on the dorsal wall of the pharynx. 



12. Compressor muscle group of the cibarium (fig, 2), — Arises on 

 one side of the dorsal wall of the cibarium, central region, and ex- 

 tends transversely across the surface to be attached on the opposite 

 side, 



13. Compressor muscles of the anterior region of the cibarium 

 (fig, 2). — Arise laterally on the dorsal wall of the cibarium in the 

 anterior region of muscle group 12; they extend diagonally anteriorly 

 to be inserted on the dorsal surface of the cibarium mesad of one of 

 the dorsal dilator muscles of the cibarium, 5. 



14. Hypopharyngeal muscle of the mandible (fig. i). — Arises on 

 the lateral wall of the mandible and is inserted on the distal end of 

 sclerite X (fig. i). This muscle was found only in Orthoptera; it 

 is, of course, common in apterygote insects and other arthropods, 



15. Anterior dorsal dilator muscle of the salivariuni (fig, i), — 

 Arises on sclerite X adjacent to muscle 16 and is inserted laterally 

 on the ventral wall of the hypopharynx, 



16. Dorsal salivary cup muscle (fig. i). — Arises on the inner sur- 

 face of sclerite X and is inserted, near the center, on the dorsal sur- 

 face of the salivary cup. 



17. Anterior salivary cup muscle (fig. i). — Arises laterally on the 

 ventral wall of the labium adjacent to the palpal base and is inserted 

 laterally in the anterior region of the salivary cup anterior to muscle 18. 



18. Lateroventral salivary cup muscle (fig. i). — Arises laterally at 

 the base of the prementum near the dorsal surface and is inserted 

 laterally in the anterior region of the salivary cup, 



19. Muscle of the hypopharynx (fig. i). — Arises on the tentorial 

 bridge immediately dorsad of muscle 20 and is inserted laterally on 

 the base of the hypopharynx. 



20. Dorsal {anterior) muscle of the labium (figs, i, 3), — Arises 

 on the tentorial bridge immediately dorsad of muscle 21 and is in- 

 serted laterally in the anterior region of the dorsal wall of the labium. 



