1908.] OF SNAKES OF THE GENUS CORALLUS. 155 



within the body of serpents generally as of systematic impor- 

 tance. The following are the corresponding facts relating to 

 Corallus caninus : — 



Length of body to cloaca, 24 inches. 



From snout to heart, 9 inches. 



From heart to liver, 3| inches. 



Length of liver, 5| inches. 



From end of liver to gall-bladder, 11 inches. 



These measurements, though incomplete *, indicate a closer 

 agreement with Corallus cookii than with the Madagascar species, 

 as will be evident from a comparison with the tables on pp. 150 

 & 152. At the same time, there is perhaps some approach to the 

 latter in the comparative closeness of the end of the liver to the 

 gall-bladder. Moreover, the liver in Corallus caninus has a long 

 thin " tail," measuring no less than an inch and a half. This, 

 again, is a slight approach to Corallus madagascariensis, inasmuch 

 as the tail of the liver in both species is about one fourth of the 

 length of the entire liver, while in C. cookii there is evidently a 

 tendency for this thin posterior prolongation of the liver to 

 disappear. This, however, is nearly the only point in the internal 

 anatomy of Coralhts caninus in which I have ascertained a 

 likeness to the Madagascar species at all more pronounced than 

 to Corallus cookii. In examining the liver I naturally sought 

 with care for vestiges of the umbilical vein. These are quite 

 obvious, and I am even inclined to think that this vein is fairly 

 well-developed in the present species, though its condition did 

 not permit of an accurate maj^ping of the coui"se of the vein. 

 However, a strongish vein — the further course of which along the 

 body- wall I am unable to state — dips down from the body- wall to 

 the liver. Arrived upon the surface of the liver its calibre becomes 

 increased, as is often the case with the umbilical vein in the Boine 

 snakes ; but, instead of joining the postcaval, it appears to end in 

 the liver-substance. But its former connection (?) with the post- 

 caval is indicated by a furrow deeply marked which connects the 

 vein with the postcaval, continuing in the same straight line as 

 the vein would traverse were it to pass directly to the postcaval. 

 I think, therefore, that this vein is the persistent umbilical and 

 not merely a branch of the epigastric. I may point out that, if 

 this opinion is well founded, the present species of Corallus agrees 

 with its American congener. 



As I have already pointed out, the Madagascar and the South 

 American species of Co7-allus differ in the relations of the 

 pancreas to the spleen. I am bound to state that Corallus 

 caninus seems to be more like Corallus madagascariensis than 

 is to Corallus cookii in these matters. That is to say, there is no 

 thin process of the pancreas putting the pancreas into actual 

 contact with the anteriorly lying spleen. On the contrary, the 



* It was desirable to injure the snake as little as possible. 



