1906.] BESPIKATORY SYSTEMS IN THE OPHIDIA. 517 



It will be remembered that in Python^, contrary to what is found 

 in Utmectes t, and even, though to a less extent, in Boa t, the 

 umbilical vein is represented in the adult by a rudiment only. 

 Nevertheless this rudiment was quite obvious in the several 

 examples in which I sought for, and succeeded in finding, it. I 

 am therefore inclined to regard my inability to find the least 

 trace of such a rudiment in Corallus as evidence that the vein has 

 completely disappeared in that snake. This state of afiairs is, 

 however, more like that of Python than of the two Boine genera 

 Eunectes and Boa. The vein running from the front end of the 

 liver to the pericardium showed no indications whatever of a 

 branch. 



Although in this particular the evidence afforded is rather in 

 favour of "the placing of Corallus in the Pythonine subdivision, 

 it has less value in that it is a negative character. 



The intercostal arteries offer a positive character pointing in 

 the same direction. In Boa, Uimectes, and Eryx § the intercostal 

 arteries are apt to arise at widely separated intervals from the 

 aorta, a single branch thus arising running backwards or forwards 

 or both for a considerable distance, and giving off a regular series 

 of branches to the right and left of the dorsal middle line of the 

 body. In Python, on the other hand, as the researches of Jacquart |i 

 and my own observations have shown, the intercostals arise 

 regularly from the main trunk of the aorta. Each artery springs 

 separately from the aorta and divides below into two, one for 

 each side of the body. In E7yx, &c. each arterj^ may leave the aorta 

 separately from the point of its origin. There is but a slight 

 development at most of secondary longitudinal intercostal trunks. 

 Now it is important to record the fact that in these charac- 

 teristic features Corallus is on the side of Python, and departs 

 equally from the conditions observable in the Boas. 



I do not venture upon any further details concerning the 

 circulatory organs for the reasons already stated. 



The position of the viscera in the Ophidia is of importance to 

 note as a means of comparison between various genera and even 

 various species. 



In the present serpent, which measured 55 inches including the 

 short tail, the liver begins fairly close to the heart, its anterior 

 end being only 2^ inches from the apex of the heart. The liver 

 itself presents peculiarities worth noting. It is very long, measuring 

 12| inches altogether. Of these the last 4 inches belong to a 

 backward extension of one of the two lobes. It is very usual for 

 this lobe to extend back beyond the other lobe among Ophidia,. 

 and the proportions vary somewhat in different cases. I have 

 not, however, as yet had the opportunity of dissecting a snake in 



* Beddard, " Contribution to the Anatomy of the Ophidia," P. Z. S. 1906, vol. i. p. 28. 

 I may take this opportunity of recording the fact that Tytlion molurus and P. regiuif 

 ao-ree with P. seha in the retention of a similar rudiment. 



t Beddard, loc. cit. p. 18. J Snpy^a, p. 514. 



§ Beddard, loc. cit. p. 33, and P. Z. S. 1904, vol. ii. p. 109, text-fig. 19. 



II Ann. Sci. Nat. (4) vol. iv. 



