In this less advanced embryo (No. 836) the umbilical veins still pass around the liver to reach the sinus venosus.
Text and drawing from Fig. 13-8 O'Rahilly and Müller, 1987.
Keywords: amnion, coelom, coelomic surface, dorsal pancreas, hepatic plexus, hepatic trabeculae, left hepatocardiac vein, left umbilical vein, liver, pericardial cavity, postcardinal vein, right hepatic horn, right hepatocardiac vein, right umbilical vein, sinus venosus, specialized coelomic wall
Source: The Virtual Human Embryo.