OCR Text |
Show 300 MR, R, H. BURNE ON THE [Apr. 18, in conjunction with the tendons of the supra-clavicularis and supra-coracoideus. Fiirbringer states that in Chelone and Sphargis the tendon of the pectoralis divides into two, one of which extends on to the radius. I did not see this part of the tendon in my specimen. Supra-clavicularis (text-figs. 57-61. 44a).-Origin: from a median raphe and the plastron in front of the clavicle; from the anterior, ventral, and posterior surfaces of the clavicle. Insertion : upon the lateral process of the humerus. This is a very large mass of muscle, measuring, at 6 cm. from its insertion, 10 cm. x 2 cm. Towards its insertion its deeper parts blend with the supra-coracoideus. Fiirbringer states that this muscle is weak in Sphargis, but peculiarly strong in Chelone. Text-fig. 59. Dermochelys coriacea, left shoulder-girdle, anterior view. 38. Capiti-plastralis, 40 a (see text), 44 a. Supra-clavicularis, 50 a. Deltoideus (clavicular part), 50 b. Deltoideus (scapular part), 52. Scapularis. Supra-coracoideus (text-figs. 58 ifc 61. 44 b).-Origin : from the anterior margin and median end of the dorsal and ventral surfaces of the coracoid. Insertion : upon the lateral process of the humerus. This is a relatively thin sheet, separable at its origin with some difficulty from the coraco-antebrachialis. Coraco-brachialis brevis externus (text-figs. 58, 61, & 64. 4 5 ).__ |