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Show 1004.] CIRCULATORY SYSTEM IN T H E OPHIDIA. 359 Parietal Ported Veins.-The veins which arise from the dorsal region of the body-wall to be connected wuth the portal system are, as usual, comparatively few in number. The first vessel springs from the left side of the dorsal middle line, not far from the beginning of the liver. Five intercostals intervene before the origin of the second vein, which has three roots and passes dorsally of the aorta instead of ventrally, as is the case with the first vein. There are only two more veins before the end of the liver. The first of these springs, like the last, from the right side of the median line and passes dorsally of the aorta; it has two roots. So has the fourth vein, which is left-hand in origin and passes ventrally of the aorta. Behind the liver are five more veins, which are all right-hand and pass dorsally of the aorta. The last of the series corresponds to the superior mesenteric artery; it is right-hand in origin, passes dorsally of the aorta, and arises from at least six roots. The next portal vein belongs to the anterior suprarenal body. Abdominal Portal Veins.-It is by no means always the case that it is possible to observe these veins with clearness. They are, however, plain in the present specimen, and I counted nine veins entering the liver ventrally, of which many were accompanied by an affluent of the epigastric artery. The first two of these veins enter the liver-substance separately. The next five or six combine to form a short longitudinally-running trunk, and which, so far as I can ascertain, enters the liver at two separate points. Then Text-fig, 74. Epigastric vein of Ophiophagus. Ep., epigastric vein with branches to liver; L., liver ; V.C.I., vena cava. follow three vessels situated at approximately equidistant intervals, each of which is formed by the union of either two or three trunks. All of these vessels enter the left liver-lobe, which ends shortly behind the last of them, being much shorter than the right liver-lobe, which is quite one-third longer. The partial union of these before entering the liver seems to m e to be a Lizard-like character. N A I A TRIPUDIAXS. The anterior vertebral artery in this Snake has a long course in the neck before it enters the parietes. It only becomes lost to view about half an inch behind the head. The intercostal branches of this artery form an absolutely continuous series |