CROCODILIANS, LIZARDS, AND SNAKES. 



197 



mesentery. The tliree mesenteries now described are the only ones which are 

 universally present which bind the liver. Tlie following sheets are present in 

 various types : Generally the right hepatic and the gastrohepatic give off sheets 

 to the right and left lungs respectively, constituting the right hepatopulmonary and 

 gastropulmonary mesenteries. A sheet occasionally goes off from the gastrohepatic 

 to the left body wall, forming the left gastro-parietal mesentery. This is frequently 

 represented by a narrow baud, and occasionally, as in Dipsosaurua, it joins the 

 small intestine just beyond the extremity of the gastrohepatic sheet. This is not 

 reijresented on the accompanying diagram. In Heloderma a distinct sheet extends 

 from the left border of the liver to the left body wall, forming the left lateral hepatic 

 mesentery. In Folyclirus and Anolis the left lung, instead of being attached to the 

 gastrohepatic mesentery, is attached by a sheet to the left border of the liver, form- 

 ing the left hepatopulmonary mesentery. In Varanus salvator there is a short median 

 gastrohepatic sheet. In Varanus, owing to the anterior position of the lungs, they 

 have no hepatic or gastric connections. In no Saurian have I observed a right 

 hepatopulmonary sheet, as the right hepatic mesentery takes in the right lung in 

 its course. The latter extends along the apical strip of the right lobe of the liver 



Fig. 5. 



DlAGEAJI OF PERITONEUM OF SAURIA, WITH ALL THE FOLDS DISPLAYED BY A TRANSVERSE SECTION 

 NEAR THE MIDDLE OP THE LIVER. 



L, liver; ST, stomach; RL, right lung; LL, left lung; JJO, epigastric peritoneal fold; LHT and 

 -RHF, left and right hepatoventral folds; JfLR ami iiiT, right and left lateral hepatic folds ; RH, 

 right hepatic; G77, gastrohepatic ; LHP ani RHP, left and right hepatopulmonary folds. 



to the genital mesentery in many genera. In Tupinamhis, Dracwna, and some others 

 the right hepatic extends as a strong sheet to the right body wall, forming, with an 

 equally strong gastroparietal of the left side, a kind of diaphragm. In many genera 

 the right hepatic sheet is connected with the stomach, especially at its proximal part. 

 Besides the hepatic and gastric mesenteries, there are those which inclose the 

 internal genitalia, the urinary bladder, and the corpora adiposa. The genital 

 mesentery is sometimes quite extensively free, and is always so anteriorly, espe- 

 cially where it supports the wide fontanelle of the oviduct. There is no mesentery 

 of the corpora adiposn, and a pouch only in those easels where those bodies project 

 freely into the abdominal cavity, as is frefjuently the case. The cystic mesentery 

 is a transverse fold of the peritoneum which lines the inferior wall of the pelvic 

 cavity, and which incloses th(^ urinary bladder when it is present. 



The integument of the Sauria is divided into scales of a great 

 variety of structure. Some of them are ossified, and in such cases are 

 traversed by canals (Scincidfe). Others are produced into acute apices, 

 which are ensheathed by a very hard epidermis, which becomes formi- 



