1895.] LUNGS OF SIfAKES, AMPHISB^NID^, ETC. 701 



doubtless Prof. Cope himself among the first, will admit that the 

 animals represented in (7) pis. xii., liii., xiv., xv., and xvi., must 

 have been prepared for sketching by cutting through the mem- 

 branous tissue that conuects the alimeutarj canal with the mid- 

 dorsal line of the liver (and carries veins from the alimentary- 

 canal to the liver), and also the membranous tissue which passes 

 to the right of the alimentary canal and attaches the liver to the 

 dorsal body-wall and bears other blood-vessels to the liver ; and 

 will see that after cutting of these doi-sal attachments of the liver 

 that organ has either been merely pushed aside, as in pis. xiii. and 

 xiv., or on the other hand has been turned over bodily through 

 some 180 degrees, as in pis. xii., xv., and xvi. In either case the 

 position of the lung with regard to the liver is not the natural 

 one, and the impression is conveyed that the lung lies more to the 

 left of the median plane than it really does. 



That the membranes have been cut through, and the liver dis- 

 placed as described, will, as remarked, be granted by those who 

 have carefully studied this region of the snake's body, because of 

 the unnatural position of the liver ; but the displacement with 

 inversion through some 180°, in the case of the snakes figured on 

 plates XV. and xvi., will be recognized by all who remember that 

 in Snakes, as in other animals, the postcaval vein enters the right 

 half of the liver and not the left. The figures, in fact, are drawn 

 in all good faith and tell their tale truthfully when carefully 

 questioned, but the lettering and their appearance on the face of 

 them are misleading. 



The most striking figure is that of Charina bottce [J. c. plate xii.] 

 [one of the more normal two-lunged forms], where, after cutting 

 through the dorsal attachments of the liver, the lungs and liver 

 have evidently been turned over together in one piece to the right, 

 so that the lungs lie ventral to the liver, with the larger right 

 lung on the left and described as the left, and the smaller left 

 lung on the right and described as the right. 



We may now turn to consider the case of Reterodon platyrhinus 

 [the curious forward diverticulum of whose chief lung has long 

 been known ^]. Cope figures this snake in both of his papers 

 (7) pi. XV. and (8) pi. xxviii., and on account of its special interest 

 in another respect I figure part of it here also [PL XL. fig. 1]. 



In this snake the position of the rudimentary lung with regard 

 to the other, which is just as represented in Cope's figure, is at first 

 view very deceptive. 



It will be seen that the smaller rudimentary lung lies ventral to 

 the other and to the right of the trachea. Xot only, howevei-, 

 does the position of the larger lung with regard to the other 

 organs, and notably to the blood-vessels above mentioned, prove 

 that larger lung to be the right lung, but sections [see figs. 2-4], 

 showing as they do a corresponding rotatory displacement of the 



' See Duvernoj, 'Lecons d'Anat. comp. de &. CuTier,' 2nd ed. torn. vii. 

 p. 138 (1840). 



Peoc. Zool. Soc— 1895, No. XLV. 45 



