466 MR. G. W. BUTLER ON THE SUBDIVISION OF [NoV. 19, 



median ventral ligament behind it, and take a more or less oblique 

 course across the liver. Sometimes there is more than one such on 

 a side. 



I would call these the oblique ligaments of the liver. 



These ligaments, when present, appear, in certain cases, to be 

 continuous with the membranes that bear the forward continuations 

 of the Miillerian ducts (oviducts), and are specially noticeable in 

 the case of the Chameleon, where they form broad sheets of mem- 

 brane constituting a Icind of ventral diaphragm ^ 



The oblique ligaments can be traced in Lacerta, JJromastyx, 

 Ayneiva, Chamceleon, and others, but their number, distribution, and 

 degree of development is different in different forms ; and I call 

 attention to them chiefly on account of the light they may throw 

 on the nature of certain membranes in the Crocodiles. There are in 

 these animals (c/". p. 469) certain well-defined ventral ligaments of 

 the liver, which completely mark off the more median portion of 

 each lobe from its antero-lateral corner, and seem to correspond to 

 these inconspicuous ligaments in the Lacertilia, but not truly to 

 anything in Birds. 



I am inclined to regard such oblique ligaments as complementary 

 to the pulmo-hepatic ligaments ; that is, to consider that they serve 

 to unite the liver to the body-wall in those forms in which the tissue 

 corresponding to the avian diaphragm, to which the last-mentioned 

 ligaments are attached, does not itself become attached to the body- 

 wall. 



The more or less marked folds of peritoneum, which carry the 

 forward continuations of the Miillerian ducts, seem (c/l p. 462) to 

 mark the line along which an avian diaphragm might be expected 

 to arise; and they probably exercise one of the functions of a 

 diaphragm, in rendering a certain protection to the lungs; but I 

 would not advocate any closer homology between these membranes 

 and the diaphragms of either Birds or Mammals. 



The relation of the lungs to the body-cavity in the Monitors is 

 referred to in my paper on the " Fat-bodies," to be subsequently 

 read, and I have nothing further to add here. 



(6) The TeiidcE. 



The condition in Tupinambis teguixin (Tej'us teguexim. Gray) is 

 very interesting. 



We have here (c/. Plate XLYIII. figs. 31-34) a post-hepatic 

 septum (/5), apparently homologous with the ventral (or so-called 

 " omental ") portion of the post-hepatic septum in birds (the ventral 

 side of which is shown in fig. 29, /G), and perhaps to the greater 

 part of the post-hejmtic septum in Crocodiles (figs. 40-43, /3), 



This well-marked post-hepatic septum at first strikes the observer 



^ Such oblique ligaments do in their adult relations rather suggest part of 

 the embryonic mammalian diaphragm. They attach the liver to the body-wall 

 posteriorly and ventrally to the attachment of the liver to the lungs or media- 

 stinum (compare with this Plate XLVI. fig. 4, dph.). 



