~_M. adductor mandibulae posterior._~--The origin is fleshy from the anterodorsal and anterior surfaces of the quadrate body, from the anterodorsolateral, medial and anterior surfaces of the orbital process of the quadrate. The muscle also has an origin from the otic process of the quadrate, partly fleshy and partly by a slight aponeurosis. The insertion is fleshy on the dorsal and lateral surfaces of the mandible immediately anterior to the articulating surface. This muscle also has extensive insertion on the medial side of the lower mandible dorsal to the insertion of _M. pterygoideus dorsalis medialis_ and posterior to the origin of _M. pseudotemporalis profundus_ (figs. 1, 3, 5, 17, 18, 19 and 20).
The fibers of _M. pseudotemporalis profundus_ can be distinguished from the fibers of _M. adductor mandibulae posterior_ because the pterygoideus nerve passes between the two (Lakjar, 1926:55). Rooth (1953:255-256) considers as part of this muscle the ventral aponeurosis of _pars profundus_ of _M. adductor mandibulae externus_ and all the fibers ventral to it. But I could not justify the inclusion of that aponeurosis as part of _M. adductor mandibulae posterior_ in the doves because none of the fibers of _M. adductor mandibulae posterior_ as I have described it were attached to that particular aponeurosis.
~_M. protractor quadrati._~--The origin is fleshy from the posterior wall of the orbit medial to the foramen of the trigeminal nerve and also medial to the origin of _M. pseudotemporalis superficialis_. The origin describes an arc in the horizontal plane until it reaches the interorbital septum and the optic nerve. The insertion is fleshy on the posteromedial edge of the body of the quadrate and the orbital process of the quadrate and on the otic process of the quadrate. The muscle also inserts on the ventromedial surface of the orbital process of the quadrate and the adjacent area of the body of the quadrate (figs. 5, 7, 9, 11, 13-18).
_M. protractor quadrati_ possesses many fibers that arise from _M. protractor pterygoidei_. Consequently, it is difficult to determine the exact extent of the origin or the insertion of either muscle.
~_M. pterygoideus ventralis._~--Contraction of this muscle retracts the upper mandible by moving the palatine posteriorly, and simultaneously adducts the lower mandible.