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Show 194 DR. R. Vi. 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 particular structure and its differences are concerned. Further it will be seen, from what has been set forth above, that Heloderma agrees with Varanus in the anatomical 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 such 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 right 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. The right corpus 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 commissures 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 constituting these masses is of a pale 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 the structures 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 we gave with sufficient 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, the pancreas, and part of the intestines. In position the liver lies somewhat to the right side of the coelom, and the right corpus |