SHOULDER-GIRDLE. 73 



B. 117. Tenth to thirteenth dorsal vertebrae of a Chimpanzee 

 (Anthropopit/iecus troglodytes), showing ribs attached to all 

 the transverse processes. 



SHOULDER-GIRDLE. 



B. 118. Right scapula and clavicle of a Tasmanian Devil 

 (Sarcophilus [Dasyurns] ur sinus). The clavicle is attached 

 by ligament to both the coracoid and acromion processes 

 of the scapula. 



B. 119. Anterior part of the sternum with the clavicles of an 

 Armadillo (Dasypus sexcinctus), showing the sterno-clavicu- 

 lar articulation. Each clavicle is attached to one of the two 

 anterior processes of the expanded manubrium sterni by a 

 ligament in which are embedded two nodules of cartilage. 

 Owing to the position of the sternal end of the clavicle 

 directly dorsal to the manubrial process, the ligament under- 

 goes a ventral twist in passing from one to the other. 

 Hoffmann, Niederl. Arch. f. Zool., t, v. 1879-82, p. 66. 



B. 120. Left scapula and clavicle with the distal ends of the first 

 two ribs of Three-toed Sloth (Brady pus tridactylus). The 

 clavicle is rudimentary and represented only by a nodule 

 of bone imbedded in a ligament that passes between 

 the sternal extremity of the first rib and the coracoid. 

 Humphry, Jour. Anat. & Physiol., vol. iv. 1870, p. 26. 



SHOULDER. 



B. 121. The right anterior extremity of a Bull - Frog (Rana 

 catesbiana] . 



The shoulder-joint is laid open, and the capsule turned 

 back, to show an interarticular ligament passing from a 

 depression in the head of the humerus to a depression in the 

 centre of the glenoid cavity, and attached also to the inferior 

 margin of that cavity. A bristle is passed behind this 

 ligament : a small synovial bag projects into this joint just 

 above the insertion of the ligament. 



This additional security against dislocation of the shoulder- 

 joint appears to be necessary in the frog, to obviate the 



