318 MR. R. H. BURNE ON THE [Apr. 18, 



Anteriorly, part of the ventral wall of the sac is attached to the 

 dorsal surface of the left lobe of the liver in continuation of the 

 mesentery of the transverse segment of the intestine and also to 

 the lateral border of the liver. Otherwise, the anterior attach- 

 ments of the sac were not very satisfactorily made out, but in all 

 probability it merges with the peritoneum that lines the anterior 

 end of the abdominal cavity. Another detail that does not 

 appear so clearly in my notes as I could wish, is the exact point 

 at which the oesophagus comes to lie entirely free within the 

 sac. 



In Emys, although there is no similar sac of anything like 

 these dimensions, there is an arrangement of the mesenteries that 

 seems to represent it in a very much less developed condition. 

 The cesophagus and stomach are suspended from the deep sur- 

 face of the liver by a mesentery continuous with that which 

 supports the transverse segment of the small intestine. This is 

 no doubt comparable to the ventral wall of the sac in Dermochelys. 

 But there is also a more dorsally placed and much looser sheet of 

 mesenteiy that extends from the peritoneal lining of the anterior 

 parts of the abdominal cavity to the stomach and lower end of the 

 cesophagus. This, which I take to i-epresent the dorsal wall of 

 the sac, encloses between itself and the first-mentioned mesentery 

 a deep povich that lies behind the liver in the bend formed by the 

 oesophagus, stomach, and intestine, but does not enclose within its 

 cavity any fi-ee parts of the alimentary canal. The great develop- 

 ment of this mesenteric sac in Dermochelys is most probably to be 

 referred to the excessive length and bent form of the oesophagus 

 and to the much complicated stomach. 



Ten inches beyond the point of entry of the bile-duct into the 

 intestine wall, a free mesenterial fold appears vipon tlie anti- 

 suspensory surface of the gut. The line of attachment of the fold 

 is at first rather to one side of the mid-ventral line of the intes- 

 tine, and in this part the fold is deep, and owing to the shortness 

 of its free border compared with the length of its attachment 

 forms a pouch in which are contained three coils of the gut. 

 Beyond the region of the pouch the fold I'apidly diminishes in 

 depth and continues along the ventral surface of the intestine for 

 some 16 inches. It terminates by branching oil' to either side to 

 lose itself in the doi-sal mesentery. In the angle between these 

 two terminal folds is a small pigmented nodule, which may 

 possibly be an extremely vestigial Meckel's diverticulum. I can 

 find no indication of this ventral mesenteiy in Emys. 



Food. 



With the exception of the mouth, in which there was a small 

 Teleostean fish, the only part of the alimentary canal that con- 

 tained food was the tubular region of the stomach. In this part 

 there were numerous tests of compound Tunicates, several small 

 simple Ascidians, and a small piece of seaweed. 



