308 PROCEEDINGS OF THE ACADEMY OF [1896. 



THE MESENTERIES OF THE SAURIA.i 

 BY E. D. COPE. 



Examination of the literature shows that this subject has been 

 nowhere adequately treated. The most considerable paper is one 

 by Dr. F. E. Beddard in the Proceedings of the Zoological Society 

 of London for 1888. This, however, includes an examination of 

 a limited number of genera, (eight) only. The present paper is 

 founded on a study of most of the genera of all the families, except- 

 ing in the cases of the Gecconidse and Agamidie, where my oppor- 

 tunities have been more restricted. I am indebted for this material 

 to the U. S. National Museum, the collections of the Academy 

 of Natural Sciences of Philadelphia and my own. 



A fold suspends the alimentary canal from the median dorsal line, 

 forming the dorsal or epigastric mesentery (E G). No other mesen- 

 teries bind the alimentary canal, except the stomach, and sometimes 

 the adjacent portion of the small intestine, which have other connec- 

 tions. The liver, on the other hand, has several mesenteric connec- 

 tions, as follows : Its ventral face has usually a single sheet connect- 

 ing it with the median ventral line, but in rare instances it is bifurcate 

 posteriorly (Scincidffi generally), or even double (Tiliqiia, LHV, 

 RHV). This sheet, or one of them, is continued along to the ante- 

 rior abdominal artery to the ventral wall, and sometimes along the 

 gall-duct to the pyloric part of the small intestine. Each border of 

 the liver is twice or thrice concave above, in adaptation to the 

 stomach and lungs in the types where the latter extend so far poste- 

 riorly, which is the usual arrangement. From the left hand ridge 

 thus produced, a sheet or mesentery extends to the stomach, form- 

 ing the gastrohepatic mesentery (GH). It is sometimes median 

 in position. From right hand superior angle a mesentery ex- 

 tends to the right dorsal body wall, forming the right hepatic 

 mesentery. The four mesenteries now described are the only 

 ones which are universally present, which bind the liver. The 

 following sheets are present in various types. Frequently the 

 right hepatic and the gastrohepatic give off sheets to the right 



' Read before the American Association for the Advancement of Science, 

 Springfield meeting, Aug. 30th, 1895. 



