Platysma myoides […] which sends attenuated fibres and slips to the gular region of the hood and is lost dorsad in the fascia covering the trapezius but acquires thickness over the sternum and cervix. Thyromandibularis […] Two distinct muscles may bear this name, an externus and an internus. The latter rises by two slips from about the middle of the inner surface of the mandible and is inserted into the middle of the inner side of the thyrohyal. The greatly elongated thyrobyal passes between the two layers of integument constituting the hood, at its middle fold, and so forms a “yard” to which the lower half of the hood is bent. This inner division of the Thyromandibularis being an adductor of the bone, is the chief agent in lowering the hood and bracing its lower moiety to the side of the neck—it is antagonised by the greater part of the outer division which rises fleshy immediately behind the inner one, but nearly on the lower edge of the jaw, the origin of the mylohyoideus being between them. It immediately divides into two superposed fascicles, the deeper one being inserted into the lower surface of the thyrohyal, a little behind the insertion of the inner division—the other sub division is inserted posteriorly to the former one into the outer side of the bone for the rest of its length and acting thus advantageously is an efficient erector of the lower part of the hood.