278 



REPTILIA. 



oin its tendon to that of the deltoid. In the 

 turtles it is prolonged over all the posterior 



Fig,. 195. 



Myology of the Tortoise. 



2, pterygoideus ; 4, dilator tubse ; 29, rectus ca- 

 pitis anterior longus; 30, rectus capitis anterior 

 minor ; 31, rectus capitis posterior major ; 32, rectus 

 capitis posterior minor ; 36, intertransversarii colli ; 

 37, transversarii colli obliqui ; 39, longissimus dorsi ; 

 42, diaphragmaticus. 



face of the acromion, and is inserted a 

 little higher up than the deltoid. 



The subscapularis (/g. 201. 64) is the 

 strongest muscle of the arm ; it arises from 

 all the posterior surface of the scapula, and 

 from three-fourths of the superior face of the 

 coracoid, and runs to attach itself broadly 

 to all the anterior face of the internal tube- 

 rosity ; its coracoid portion describes nearly 

 a quarter of a circle to arrive at its destination. 

 Its action must be powerfully to rotate 

 the arm at the same time that the scapular 

 portion advances it forward. 



The teres major arises from the posterior 

 edge of the scapula, and unites its tendon to 

 that of the latissimus dorsi. 



In the turtles there is a teres minor, which 

 arises from the anterior portion of the pos- 

 terior border of the scapula, and runs to be 

 inserted close to the deltoid. 



The coraco-brachialis consists of two por- 

 tions, as in some mammalia, one of which, 

 the larger, arises broadly from the inferior 

 surface of the coracoid bone ; the other, much 

 smaller, arises between the preceding and the 

 biceps : both are inserted flear the sub- 

 scapularis into the internal tuberosity of the 

 humerus. 



It will be seen from the above account 

 that the muscles of the arm in the Chelonian 

 reptiles are very similar to those of mam- 

 malia, only their different portions are more 

 widely separated on account of the great 

 prolongation of the acromion, and of the 

 coracoid. 



Muscles of the Fore-arm. The bones of the 

 arm and the fore-arm not having undergone 

 the same distortion as those of the shoulder, 

 the muscles are less changed from the usual 

 arrangement. The biceps alone coming from 

 the coracoid bone, must necessarily follow its 



Myology of the Tortoise. 



9, obliquus oculi superior ; 10, obliquus oculi inferior ; 27, retrahens capitis collique; 52, flexor caudae 

 ischiadicus. Other muscles indicated by same letters as in preceding figures. 



movements ; it, however, always arises from 

 its anterior margin, and passes along the 

 bicipital groove when that exists in the Che- 

 lonians. It is only fleshy at its coracoidal 

 extremity ; all the rest consists of a tendon, 



which runs along the humerus to be inserted 

 into the radius. 



The brachialis internus occupies its usual 

 situation, as also does the triceps brachii ; the 

 latter, however, is proportionally small, and 



