1906.] RESPIRATORY SYSTEMS IN THE OPHIDIA. 507 



At the antei"ior end of the liver is another equally stout dorsal 

 parieto-hepatic, which also arises by three or four twigs from the 

 parietes. Between these two are smaller affluents which spring 

 from two roots. In every case, these vessels are joined by a 

 branch or branches from the stomach before entering the portal 

 vein. At the extreme anterior end of the liver the portal vein, 

 greatly diminished in calibre, is continuous with a slender vein 

 which runs along the dorsal side of the oesophagus ; this vein was 

 ti-aced forward to the front end of the heart, and apparently 

 extends rather further, but I am unable to be exact as to its 

 relationships here. It has, I think, a branch from the parietes 

 very far forward, in which case it conforms in its construction to 

 the other veins from the parietes. It is noted that these dorsal 

 parieto-hepatic veins are not in any way connected together to 

 form a continuous longitudinal vein running along the parietes 

 in the region of the liver or near to it. In the Boidte there is 

 constantly such a development of longitudinal veins in the hepatic 

 region. It is possible to compare the anterior vein, which enters 

 the portal vein in a straight line with it at the extremity of the 

 liver, to a somewhat similar vein which in Yaranus enters the 

 anterior tip of the left lobe of the liver *. 



There are also the usual branches of the epigastric vein concerned 

 with the circulation of the liver. The most anterior of these are 

 two which enter, close together, the oesophageal vein already 

 referred to as joining the portal at the anterior extremity of the 

 liver. Along the course of the liver there are also two branches 

 from the epigastric, each of which arises from that vein by two or 

 three roots. Finally, at the end of the liver a strong branch joins 

 the epigastric and portal just before the latter reaches the liver. 

 There are some further connections between the epigastric and 

 the portal andT anterior abdominal posteriorly ; but I have not 

 mapped them accurately. The occurrence of a marked anterior 

 and posterior communication between the epigastric vein and the 

 vessels of the liver appears to be general in the Ophidia. It should 

 be noted that the epigastric branches entering the liver at its 

 middle plunge into the liver-substance, and are not directly 

 connected with the portal vein. 



(2) Some Notes iqjon the Anatomy of Boa diviniloqua and 

 B. constrictor t. 



I have had the opportunity of dissecting two specimens of the 

 former Snake which have recently died in the Menagerie. I am 

 therefore able to make known a few anatomical facts which have 

 not hitherto received much attention. So far as I am aware, this 

 particular species has not been studied up to the present. Some 

 other species have been examined with regard to particular points, 



* Beddard, P. Z. S. 1906, vol. ii. 



t For a few notes on anatomj^ see Hering, Wiirttemb. naturw. Jahi-esliefte, xvi. 

 1860, p. 103. 



