194 DR. R. W. SHUFELDT ON [Apr. 1, 



part absent ; and thus it will be seen that the Lacertilia are arrayed 

 in two sections, in so far as this pnrticular structure and its differ- 

 ences are concerned. Further it will be seen, from what has been 

 set forth above, that Heloderma agrees with Varanus in the anato- 

 mical arrangemennt of its peritoneal layers. 



Corpora adiposa. — These, as I have already said, are very large 

 in Heloderma ; the right one, having a length of ten centimetres, 

 and a width of three and a half centimetres, is somewhat longer, but 

 scarcely wider than the left one. In outline, either is shaped 

 something like a hemi-ellipsoid, the plane surface facing dorsad, 

 while the convex one looks downwards and outwards. Anteriorly, 

 either one of these paired fat-masses has fully one-third of its bulk 

 turned in upon itself from without, inwards, and in sucli a manner 

 that the plane surface of the turned-in portion is opposed to, and in 

 contact with, the plane surface of the remainder of the mass. 

 These fat-bodies have rounded margins, and are throughout irregularly 

 lobulated, the lobules being of various sizes. As has been stated, they 

 are separated from the abdominal cavity by the horizontal membrane 

 of the peritoneum ; in position the riglit one extends from the 

 pelvis anteriorly to a point up opposite the middle of the stomach ; 

 while the left one extends from the pelvis anteriorly to a point 

 up opposite the middle of the liver, and dorsad to that organ. Tlie 

 right corjius adiposum sends down into the pelvic cavity a small, 

 lobulated prolongation of its mass, and in consequence this one 

 extends further posteriorly than does the left one ; anteriorly, their 

 ends are about opposite each other. Two small lobulated com- 

 missures of fat yoke these corpora adiposa together just anterior to 

 the pelvis ; if constant, they might be known as the anterior and 

 the posterior commissures of the fat-bodies. All of the fat consti- 

 tuting these masses is of a fiale straw-colour throughout, and the 

 lobules are very distinct, being simply held together by a very 

 delicate connective tissue, and by the vessels that ramify among 

 them. I found a branch of the anterior abdominal vein that passed 

 right and left coming from between their interlobular spaces, and it 

 joined the main vein in the median line. The corpora adiposa do 

 not seem to have any very firm connections with any of liie struc- 

 tures in the abdomen, and it but requires the very gentlest of pulling 

 to detach them and to lift them in toto from that cavity. In a 

 young Heloderma I find these masses proportionately considerably 

 smaller and situate very much farther beyond the pelvis ; they are, 

 too, well overlapped by the lobes of the liver, and in the case of 

 the left one it seems to be underlaid, posteriorly, by the loop of the 

 duodenum. 



The Liver. — In a former paragraph wc gave with suflficient 

 fulness the manner in which the hepatic peritoneal folds assisted to 

 hold this important organ in its place in the body-cavity. Anteriorly, 

 the heart lies, for its apical portion, between its two principal, lobes, 

 while below these latter there is brought into view the stomach, ihe 

 ))ancreas, and part of the intestines. In position the liver lies 

 somewhat to the right side of the ccelom, and the right corpus 



