I think muscles 8 and 11 are respectively the mandibular muscles and the dorsal retractor of the maxillae (The book from Christophers, 1960 on Aedes aegypti has some nice schematics on page 583).
here the description of muscles 8 and 11, taken from the book that mentioned Clément.
Muscle 8. Mandibular muscle. A small muscle on each side from the floor of the tentorium at its anterior end to the base of the mandible. These small muscles are conspicuous in transverse sections through the fore part of the head situated on each side of the buccal cavity and are so shown in the figure by Annett, Dutton and Elliott. (Mandibular muscles of Thompson; retractors of the mandibles of Robinson.).
Muscle 11. Dorsal retractors of the maxillae. A large muscle on each side from the inner surface of the tentorium about its middle to the spur of the maxilla. (Double retractors of the maxillae of Thompson; dorsal retractors of the maxillae of Robinson.)