22 



THE MAMMALIA 



[SECT. A 



VIII. A movable plate of cartilage — the epiglottis — repre- 

 sented only by a rudiment in some Amphibia and Sauropsida — 

 overhangs the slit — commonly called glottis — leading from the 

 pharynx into the cavity of the larynx. 



Clavicle 



Acromion 



Coracoid 



^.Glenoid 



cavity 



-Humerus 



Fig. 10. Shoulder girdle of an Eutherian Mammal (Man) ; to shew the reduc- 

 tion in number of elements remaining distinct. 



IX. A partition of muscular fibres, usually with a tendinous 

 centre — the diaphragm — divides the cavity of the body into two 

 parts, an anterior — the thorax — containing the heart and lungs, 

 and a posterior — the abdomen — containing the greater part of 

 the alimentary canal with its associated glands — the liver and 

 pancreas — and the renal and reproductive organs. 



