_Origin and Insertion._—Adhering closely to the skin, it generally becomes lost at the occiput; it is most highly developed in the mid-cervical region, and it gradually disappears over the caudal region. _Shape._—Delicate and ribbon-shaped. _Relations._—Superiorly it is attached to the skin. Fat sometimes surrounds the muscle. _Action._—By contraction it raises the feathers along the superior part of the neck and dorsal region. =Dermo-tensor Patagii.= _Location._—Between the root of the neck and top of the shoulder. _Origin and Insertion._—Attached to the skin in the region of the anterior part of the root of the neck, some fibers passing obliquely upward and blend with fibers of the dermo-temporalis. It blends, by a slender tendon, with that of the tensor patagii longus. _Shape._—A bundle of muscular fibers later becomes thin, delicate, and triangular in shape. _Relations._—Externally to the skin. _Action._—Auxiliary to the tensor patagii longus. A tensor of this region. The patagii are associated with the wing fold of skin which fills the angle between the arm and forearm. This fold contains elastic tissue and muscle. =Dermo-humeralis.= _Location._—Lateral thoracic region. _Origin and Insertion._—Fan-like delicate fibers from the skin in the abdominal integument, contracting into a long narrow fasciculus of fibers, again spreading out in fan-shape to be inserted to the tendon of the pectoralis major, just below its insertion. _Shape._—Triangular, fan-shape. _Relations._—Superiorly with the skin. _Action._—Controls the skin in this region. The anterior end being fixed, the muscles are raised; and the posterior end acting as the fixed point, the feathers are caused to lie close to the body. =Dermo-pectoralis.= _Location._—On each side of the chest, lying in a longitudinal manner. _Origin and Insertion._—Attached to the skin on either side of the thorax corresponding to the dermo-dorsalis. Anteriorly it disappears over the region of the origin of the cleido-trachealis, and posteriorly just behind the tips of the post-pubic parts of the pelvis. _Shape._—Thin, delicate. _Relations._—Superiorly with the skin. _Action._—The anterior part acting as the fixed point, the feathers of the chest are raised; and the posterior end acting as the fixed point, the feathers are made to lie flat. THE DERMO-OSSEOUS MUSCLES Dermo-temporalis Platysma myoides Dermo-cleido dorsalis Cleido-trachealis Dermo-spinalis Dermo-iliacus Dermo-ulnaris =Dermo-temporalis= (Fig. 18, No. 1). _Location._—From the temporal region down the side of the neck to the anterior part of the thoracic region.