144 MR. F. E. BEDDARD OX THE ANATOMY [Mar. 3, 



in- Boa and Eunectes. I could not find this vein in Gorcdlus 

 madagascariensis. In one specimen of Gorcdlus cookii, on the 

 other hand, there is a small vein arising from the postcaval just 

 after the commencement of the liver which I regard as probably 

 representing that vein. It may be that I have missed it in 

 Corallus madagascariensis ; and yet I rather fancy that it did 

 not occur in the specimen which I dissected, for it was naturally 

 carefully sought for, as being of some impox-tance in classification. 



Another example happened to allow of a more accurate descrip- 

 tion of what appears to be the persistent umbilical vein, more 

 poorly represented, or, it may be, in a poorer condition for obser- 

 vation in the other snake. The accompanying figure (text-fig. 24) 

 shows this vein and its connections. Behind the liver a single 

 epigastric vein runs along the median doi'sal line in close contact 

 with the body- wall, as in all snakes (in which it has been looked 

 for). Passing forward, this vein divides into two, at first divergent 

 and afterwards parallel, veins at a point about half an inch or so 

 in front of the posterior end of the liver. The left-hand of these 

 two veins continues to bear the characters of the epigastric vein. 

 It emits branches to the liver, which cross over or rather under 

 (as the animal is viewed on a dissection) the other vein. These 

 branches enter the liver and form a part of the hepatic portal 

 system ; there are altogether five of these, the last entering the 

 liver quite close to its anterior termination. On the other hand, 

 the second of the two divisions of the at first single epigastric 

 vein runs above, but gives off no branches to, the liver. This 

 can be seen most plainly, and, as I think, is an anatomical fact — 

 and not merely due to the vessels being invisible owing to their 

 emptiness of blood. Close to the anterior end of the liver this 

 vein receives a branch from the parallel epigastric vein, which 

 runs obliquely backwards from that vein to join the parallel 

 trunk and at this point bends downwards to reach the liver. 

 On the sui'face of that organ it dilates somewhat and narrows 

 again to be connected with the postcaval vein by at least a 

 membranous seam in which I did not observe with certainty 

 any blood. It may be pervious, but I am not quite determined 

 upon the point. There are clearly reasons for looking upon this 

 vessel as the persistent umbilical vein. If this be admitted, then 

 it follows that in this character also the American species of the 

 genus Corallus shows likenesses to the Boine rather than to the 

 Pythonine subdivision of the Boidfe, 



There is therefore in this feature also a diflerence between the 

 New World and the Old World representatives of the genus 

 Corallus, and, moreover, on the whole it may be said that the New 

 World species resembles more the Boine than the Pythonine section 

 in this particular. There is, however, b}'' no means a close resem- 

 blance between Corallus cookii and the Boas in the disposition of 

 the umbilical vein, as will be seen by a reference to my descriptions 

 of that vein in Boa and Eimectes. That there should be difier- 

 ences between individuals of Corallus cookii is not surprising in 



