COPE ON OWEN ON PYTHONOMORPHA. 311 



Professor Owen has overlooked my views as to the phylogenetic posi- 

 tion of this order, aud has ascribed to me, by implication, those I do not 

 hold. He then adds others of his own which do not commend them- 

 selves to my approval. He observes {I. c. 714), — " To call the Maestricht 

 reptile a Pythonomorph is to raise a delusive beacon, misguiding the 

 voyager in the discovery of the true course of the organic change." 

 My views as to the course of organic change in this direction are as fol- 

 lows:* — "Experience has shown that generalized orders have been the 

 predecessors of the special groups of the existing fauna. The structure 

 of the Pythonomorpha, which has so much in common with orders well 

 distinguished from each other, offers a hint of the character of the pri- 

 mary group from which both have sprung. That this order is not that 

 unknown type is clear, but the indication of affinity to it is equally un- 

 mistakable." The structure of the posterior part of the skull demon- 

 strates the correctness of this position, as it is more generalized than 

 that of either Lacertilia or OpliidiUj approximating more than either 

 that of the tortoises. In other parts of the skeleton, this order displays 

 the specialization which Professor Owen claims for it. 



In closing this discussion of the essay of a master from whom I have 

 learned much, and from whom I expect to learn more, I may say that I 

 have not attempted to exhaust the subject, but have only followed it so 

 far as to«et forth my own views so as to prevent any misunderstanding 

 of them. 



» Eeport U. S. Geol. Surv. Terrs, ii. p. 126. 



