1906. J ANATOMY OF THE OPHIDIA. 27 



kidney. These longitudinal parietal vessels are upon tl^e left 

 side of the body. 



(8) As in Eunectes murinus, the left anterior abdominal trunk 

 only is connected with the afferent renal of its side*. The 

 right-hand trunk arises from a plexus on the gut, 



(9) The azygos vein is short and developed on the right side 



only, 



(10) Attention is called to anatomical differences between the 

 two species of Eunectes, which concern the division of the pancreas 

 and spleen in E. murinus, these organs being in one piece in 

 E. noUeus. 



(2) Some Notes tipon the Venous System of Python sebfe. 



It might perhaps be supposed that after the apparently 

 exhaustive survey of Jacquart t hardly anything concerning the 

 venous system of Python remained for description. Nevertheless 

 M. Jacquart has not dealt fully with a few points of which the 

 importance was perhaps less apparent at the time when he wrote 

 than at present. Since M. Jacquart's memoir, which is abim- 

 dantly illustrated, nothing concerning the vascular system in this 

 genus has been published except a few notes by myself ± in a 

 paper dealing mainly with the arteries of a number of genera of 

 Opliidia, Those notes, however, refer to Python sjyilotes. My 

 present communication refers, as did the memoir of Jacquart, to 

 Python sebce,. . . . . , 



I have dissected during the past year or two three individuals 

 of this snake, of which one only was specially favourable for the 

 study of the venous system, owing to its fresh condition and the 

 turgescence of the veins. It was possible in this individual to 

 follow the smaller branches of the veins with ease, and no injection 

 could have produced so favourable a state of affairs for examining 

 the relations of veins. 



Having so recently studied in detail the anatomy of the venous 

 system of the Anaconda §, my object has been to compare and is 

 to set down the differences and resemblances between these two 

 genera of Boidfe— types as they are of the two subfamilies, 

 Boinfe and Pythonina^, into which systematists have divided the 

 family. The vaHdity of comparisons having a purely classificatory 

 aim is of course to some extent affected by the undoubted 

 fact that species of the same genus among the Boidte may show 

 rather important differences in their veins, as I have been able 

 to demonstrate in the case of Eryx ||. 



Afferent Renal Veins and Posterior Cardinals.— In Amphisbcena 1| 



* It is necessary to emphasise tins agreement between two species of the same 

 genus, since in Eryx there are specific differences in this respect between Eryx 

 jaculus and E. conicus, as I have shown (P. Z. S. 1904, vol. u. p. 119). 



t Ann. Sci. Nat. loc. cit. 



1 P. Z. S. 1904, vol. i. p. 362, ,.. ,_ 



§ See above. ' ^ || P. Z. S. 1904, vol. n. p. 107. 



4 P. Z. S. 1905, vol. ii. p. 485. 



