ORGANS OF DIGESTION. 393 



ends, and seldom presenting any coscal portion to retard the 

 food in its cavity. In the crocodilian family, where the 

 teeth and the bones of the face are fixed, as in mammalia, 

 and the tongue, as in these, is short, round, and fleshy, the 

 stomach is in form of a round, strong muscular gizzard, with 

 an anterior and posterior central tendon, from which muscu- 

 lar fasciculi radiate to the margins, as in many lower and 

 higher animals, and the pyloric opening is guarded, as in 

 many other saurian reptiles, with a distinct circular valve. 

 The pyloric portion of the stomach presents a small ccecum, 

 like that of a heron. The small intestine is comparatively 

 long in a few vegetable-eating sauria, as the iguana and 

 scincuSy the flesh of which is edible, and it is shorter in the 

 more carnivorous forms, and there is commonly a small but 

 distinct round ccecum- as well as valvula-coli at the com- 

 mencement of the large intestine. The coecum-coli is large 

 in scincus and small in the lacerttE, and the interior of the 

 colon is often marked with longitudinal folds or quadrangular 

 cells, but it is still destitute externally of the longitudinal 

 bands which give this part a cellular form in the mammalia. 

 The wide rectum terminates in the cloaca with the urino- 

 genital organs, as in serpents, and the intestines are sus- 

 pended freely by a complete mesentery. The peritoneum is 

 often dark coloured or spotted, as in many other oviparous 

 vertebrata, and the liver, more extended transversely than in 

 ophidia, is always provided with a gall-bladder. The spleen 

 is more distinct, and generally of a lengthened form, and the 

 pancreas is less lobated in its exterior than in the serpents. 

 The stomach being less extended longitudinally than in the 

 serpents, the ducts of the liver are shorter, and the common 

 choledochus enters apart from the pancreatic at a variable 

 distance from the pylorus. 



The chelonian reptiles subsist chiefly on vegetable food, and 

 present a higher development of the alimentary canal, and of 

 the chylopoietic glands than the more carnivorous ophidian 

 and saurian species ; and from the great length of the neck and 

 the short and broad form of the trunk, the oesophagus is 

 elongated as in ophidia, and the stomach, the intestine, and 

 the liver are most developed in a transverse direction, as seen 

 in the annexed views of the viscera of emys europcea 



