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.