~_M. pterygoideus dorsalis lateralis._~--The origin is fleshy from the dorsolateral surface of the palatine, anterior to the origin of _pars medialis_ and the insertion is by means of an aponeurosis on the medial surface of the lower mandible, lateral to the insertion of _M. pterygoideus ventralis lateralis_. The aponeurosis crosses the medial side of the insertion of _M. pterygoideus dorsalis medialis_. The fibers run in a posteroventrolateral direction and insert on the ventromedial side of the aponeurosis (figs. 1, 6, 8, 9, 13-22). In one individual, a Mourning Dove, the origin of _pars lateralis_ of _M. pterygoideus dorsalis_ extended to the pterygoid. With this one exception the muscle was uniform throughout the several species. ~_M. adductor mandibulae externus._~--This is the most complex muscle in the jaw owing to its system of tendons and aponeuroses. Three divisions of this muscle were described by Lakjar (1926:45-46) and the divisions appear to be distinguishable in the doves, but there is no clear line of demarcation for any of the parts and the following description is based upon my own attempts to delineate the muscle. ~_M. adductor mandibulae externus superficialis._~--The origin is fleshy from the most lateral area of the temporal fossa. Dorsally the origin is bounded by the base of the postorbital process and ventrally by the temporal process. The fibers converge upon a tendon that passes beneath the postorbital ligament and runs anteriorly among the fibers of _pars profundus_. The insertion is tendinous on the dorsal surface of the lower mandible in common with the dorsal aponeurosis of _pars profundus_. The insertion is immediately anterior to the ventral aponeurosis of _pars profundus_ near the medial edge of the dorsal surface on a tubercle at the posterior end of the dorsal ridge of the lower mandible.