12 MR. F. E. BEDDARD OX THE [Jan. 16, 



2. Contributions to the Anatomy of the Ophidia. By 

 Frank E. Beddard, M.A., F.R.S., Prosector to the 

 Society. 



[Received December 7th, 1905.] 

 (Text-figures 2-11.) 



COXTENTS. 



(1) Oh the Vasculav System of the Anaconda, on the Characters of the newly-horn 



Young of Euiiectes notceus, and on tlie Differences between the two Species of 

 the Genus Eunectes, viz. M. murinus and 7?. not(sus : p. 12. 



(2) Some Notes upon the Venous System of Fj/thi»i seba: : p. 27. 



(3) Some Notes upon the Anatomy of Ilysia sci/tale, bearing upon its systematic 



position : p. 31. 



(4) The Structure of the Young Bifis nasicornis, with Notes on other Vipers : p. 34. 



(5) Considerations respecting the Primitive Structure of the Lungs in the Squamata : 



p. 41. 



(1) Notes 011 the Vascular Sjjstem of the Anaconda, on the 

 Characters of the newly-horn Young of Eunectes notBeus, 

 and on the Differences between the two /Species of the 

 Genus Eunectes, viz. E. murinus and E. notjeus. 



The opportunity of examining two newly-born* examples of a 

 little-known species of Anaconda, viz. Eunectes notoius, is so 

 unlikely to be of frequent occurrence, that I have thought it 

 desirable to make as detailed a .study as possible of the veins, 

 while the fact that comparatively little is known of the venous 

 system in the genus Eunectes seemed to me to render this study 

 still more desirable. So far as I am aware, some notes by myself t 

 upon the intercostal arteries and the anterior abdominal vein are 

 all that has been published upon this genus of Boine snakes so 

 far as concerns the vascular system. 



On the other hand, there is abundant material for compaiison 

 with the anatomy of the vascular system of PyLhon%, and less with 

 that of Eryx § and Boa \,. 



External characters of Young. — The newly-l^orn young of this 

 snake retain some of the embryonic veins and the yolk-sac is not 

 completely absoi-bed. This would appear to be a great disadvantage 

 until we reflect that the Anaconda is so very aquatic an animal 

 that the young are possibly born in the water %. The navel is a 

 very large aperture in the ventral median line, measuring 14 mm. 

 X 9 mm. or 12 mm. x 7 mm. It lies A:\ or 5^ mm. from the vent. 



* These young Anacondas were born on Sept. 27, 1905, and one of them was just 

 living when it came into my hands. 



t " Notes upon the Anatomy of certain Snakes of the Family Boida;," P. Z. S. 1904, 

 vol. ii. p. 107. 



(I have not seen this memoir). 



§ Beddard, P. Z. S. 1904, vol. ii. p. 107. 



II Gadow, incorporated in Bronn's Thier. vi. Al)th. iii. 



■[[ I am indebted to Mr. Pocock for remindnig mo of this. 



