627 



opens into the left subclavian about three millimetres from its origin. 

 The anterior abdominal vein therefore in this frog has no connection 

 with the hepatic-portal vein, which was apparently quite normal, divid- 

 ing into the two principal branches supplying the liver lobes in the usual 

 fashion (I may here remark that the statement in Marshall's "The 

 Frog" that it is the anterior abdominal which divides into right and left 

 branches is obviously misleading). 



This abnormal course of the anterior abdominal vein in the frog 

 inevitably reminds us of the condition in Ceratodus where the anterior 

 abdominal vein opens into the base of the right (in the abnormality just 

 described it is the left) Cuvierian duct, and perhaps still more of the con- 



ANTERIOR 

 ABDOMINAL 



A 



LEFT 

 PELVIC 



dition in Elasmobranchs where each of the two lateral veins (the homo- 

 logues of the pelvics and anterior abdominal of higher vertebrates) opens 

 into the Cuvierian duct of its side receiving the pectoral fin (brachial) 

 vein before doing so. It may further be pointed out that these lateral 

 veins of Elasmobranchs (best termed lateral splanchnopleuric in order 

 to distinguish them from the lateral cutaneous veins with which of course 

 they have no connection) in some cases, as e. g. in Scyllium canicula, 

 anastomose across the middle line along the dorsal border of the pectoral 

 girdle, thus forming a conspicuous ventral hoop (quite undescribed in 

 the textbooks) which is perhaps comparable with the median junction of 

 the pelvic (epigastric) veins to form the anterior abdominal. 



40* 



