S28 ON THE AlililGATOR 



EXPLANATION OF PLATE II. 



Figure i* 



• 



a The heart contained in the pericardium. 

 b — b The vena cava descendens. 

 c — c The pulmonary arteries. 

 d — d Left axillary vein, or subclavian. 

 e — e Pulmonary veins. 

 f—f Left or splanchnic aorta. 

 g — g Right or systemic aorta. 

 h—h Carotid artery. 

 j — j Right subclavian artery. 

 i Trachea. 

 h Bronchia. 

 / The lungs. 

 m The liver. 



n Muscle covering the liver. 

 o CEsophagus. 



Figure 2. 



This figure represents the heart, the pericardium being opened; and a sec- 

 tion of the right ventricle and the left aorta. 



1. Sinus venosus. 



2. Right auricle. 



3. Orifice of the right auricle into the ventricle of the same side with the 

 valves. 



4. The right ventricle cut open. 



5. Orifice of the pulmonary artery. 



'6. Pulmonary artery, which being situated behind, is merely indicated. 



7. Left aorta cut open. 



8. Semilunar valves. 



9. Cartilaginous septum. 



10. The whole arterial trunk. 



11. Part of the left auricle. 



12. Attachment of the ventricles to the pericardium which is mentioned by 

 M. Cuvier. 



Figure 3. 



This represents the heart viewed behind. 



1. The left ventricle cut open. 



2. The orifice of the left anricle, with the valves. 



3. The opening into the left aorta nearly closed by the valve. 



4. The common tube for the right aorta, partly cut open. 



• The latter of the double Utters in Figure I, have reference to Figure 2, in tlie Pla'.e. 



