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-girtUe, antevior 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 & 61. 44 b). — Origin : from the 

 anterior margin and median end of the dorsal and ventral 

 surfaces of the coracoid. Insertion : upon the latei-al process of 

 the humerus. 



This is a relatively thin sheet, separable at its origin with some 

 difficulty from the coi-aco-antebrachialis. 



Coraco-hrachialis brevis externus (fcext-figs. 58, 61, & 64. 45). — 



