REPTILIA 



579 



chiefly animal matter possess intestines only a little longer than the 

 body. The accessory glands, liver and pancreas, function as in other 

 vertebrates. 



External jugular vein„ 



Brachial vein 



Scapular vein 



Subclavian vein 



Thyreo-5capularvein. 

 Right prccavfll vein. 



Gall bladder- 



Poslcaval vein 



SiniiS veno3us 



Right auricle 



Pancreas 



Postcaval vein 



Kidnej/ 



Small intestine.. 



.Trachea 



.Cervical artery 



Esophagus 



..Lung 



Axillaryiartery 



.Left aorta 



.Thyroid gland 



..Subclavian artery 



.Brachiocephalic apter_y 



.Pulmonary artery 



.Left lobe of liver 



.Ventricle 



.Stomach 



.Anterior abdominal vein 



_Sapepiop mesenteric artery 



_ Ovary 



.Dorsal aorta 



.Oviduct 



.Renal portal vein 



_Lar^e intestine 



.Openini^ of oviduct 



.Cloaca 



-tJrinary bladder 



_Anu5 



Fig. 303. — Dissection to show internal organs of tlie turtle, Pseudemys troostii 



elegans, ventral view. 



Respiratory System 



The respiratory system is adapted for breathing air only, re- 

 gardless of the fact that turtles spend the greater part of their lives 

 in water. The organs composing the system are the nostrils, 

 pharynx, trachea, bronchi, and lungs. An indispensable accessory 

 structure is the htjoid apparatus. Since the ribs are made fast in 

 the carapace, breathing cannot be accomplished in the usual vertebrate 

 manner; hence, the hyoid apparatus, located in the gular region, 

 functions as a pump and the turtle seems to swallow air. The lung 



