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Show 466 MR. F. E. BEDDARD ON THE [Nov. 28, This appears to me to be a reminiscence or a prophecy of the forwardly extended portal of Hatteria. The anterior abdominal vein gives off on each side before the union of its two roots a well-developed lateral abdominal vein, so common a feature in the Lacertilia. It is a noteworthy fact that some of the venous trunks within the liver appear upon the surface of that organ instead of being entirely concealed within its substance. Almost the whole of the vena cava is thus exposed and a considerable section of the hepatic vein. Another difference from the conditions usually, if not always, to be observed among the Lacertilia is the total absence of dorsal parieto-hepatic veins. This might at first appear to be a point of likeness to the Crocodilia, among which the absence of these veins has been asserted. (2) Notes on certain Veins in the Crocodile. Parieto-hepatic veins in Crocodilus acutus.-As there appears to be a considerable conflict of opinion as to these veins in the Crocodilia, coupled no doubt with actual differences in different genera, it is perhaps worth while to record the condition of the parieto-hepatic veins in Crocodilus acutus. Contrary to what is to be met with in many Lizards and Snakes*, this Crocodile has three sets of parieto-hepatic vessels, viz. ventral, dorsal, and lateral. The two former alone exist in the Squamata, so far as we know at present. The dorsal parieto-hepatics exist on both sides of the vertebral column. On the left side they are most extensive and have the following arrangement:-There are five trunks which correspond to as many ribs. The three anterior of these, of which the second and third are the stoutest, combine to form a common trunk, which enters the liver (naturally the left lobe) near its posterior extremity. These vessels, where they emerge from the parietes, receive, each one of them, an intercostal. The last of these three vessels (i. e., that which is most remote from the heart) gives off two branches. One of these seems to be of some morphological importance ; the other appears to be less important. The latter is a branch which joins the last intercostal, which takes a share in this section of the hepatic portal system. The vessel in question runs along the " diaphragm," and, receiving the branch already referred to, entei's the liver independently of the main dorsal parieto-hepatic trunk. The branch which I regard as of some little morphological importance arises from the bend of the third of the first three affluents of the dorsal parieto-hepatic; it receives an intercostal and then perforates the dorsal mesentery and joins the system of parieto-hepatic vessels of the right side. I regard this vessel as of importance because it seems to represent a corre- * In all snakes, so far as my own experience goes. |
