1896.1 Zoology. 147 



of Natural History, containing a communication etf Mr. <i. A. Boulen- 

 ger; " Remarks on the value of certain cranial characters employed by 

 Prof. Cope for distinguishing Lizards from Snakes." Boulenger shows 

 also that Cope's statement, in regard to the relations of the squamosum 

 to the quadrate of the Lacertilia, is quite incorrect. 



that I have not yet made clear to Dr. Baur my petition as to this cle- 

 ment in the Reptilia. The ground for it is paleontologies], :md when 

 Dr. Baur considers the question from this standpoint, he will probably 

 find some of his very positive assumptions not proveable at present 



In the first place, we agree as to the identity in the Lacertilia. Py- 

 thonomorpha and Ophidia of the element which he calls Squamosal, 

 and which I call paroccipital. Whatever be the place of this element 

 in the Mammalian skull, it has certainly not been proven to be the 

 squamosal, hence I object to the name which Dr. Banr uses for it, in 

 which position I agree with various authors. It remains to be seen 

 whether the term paroccipital, which 1 have hitherto used, be appro- 

 priate. I must here repeat that at no time since 1871 have I con- 

 founded it with the opisthotic of Huxley, not even in those cases (as Tes- 

 tudinata) where I have supposed the two elements to be fused together. 

 Now the characters of this paroccipital in the Pythonomorpha are 

 such as to suggest strongly that it represents the dismembered distal 

 part of the paroccipito-opisthotic of the Testudinata. This character 

 I pointed out in 1870, and it deserves more attention than it has re- 

 ceived from Dr. Baur and other authors. It cannot be seen without 

 taking to pieces the region to which the quadrate is articulated. 

 When this is done it is found that the paroccipital enters as a cone 

 between the exoccipital and petrosal, and extends inwards in Mosa- 

 saurus nearly to the region of the semicircular canals. Nothing like 

 this is to be found in the Lacertilia. The question now arises, what is 

 the meaning of this structure ? As the Pythonomorpha is a cretaceous 

 type, it is evident that it is a survival of some primitive condition, and 

 not a derivative of the condition found in the later order of Lacertilia; 

 where the paroccipital is entirely superficial in its connections. On 

 the contrary, the character of the Lacertilia has been more probably 

 derived from that of the Pythonomorpha by the loss of the proximal 

 part of the paroccipital. 



In the Testudinata the paroccipito-opisthotic has not been observed, 

 according to Baur, to consist of two elements distinct at some stage of 



