COPE ON GEOLOGY AND VERTEBRATE FOSSILS. 597 



to present points of affinity to the Mammalia. In 1867,* the writer 

 stated it as his belief that they were connected by structural resem- 

 blances with the Birds, chiefly in respect to the tibia, fibula, and tarsus. 

 In the following' year, Professor Huxley, influenced by the sffnie and a 

 number of other, especially pelvic, characters, observed in English 

 material, also came to the conclusion that the Binosauria are related 

 to the Birds. Since that time, Professor Seeley has expressed objec- 

 tions to this view, and Mr. Hulke has adduced facts respecting the 

 structure of the pelvis in support of it. The material above described 

 does not diminish the weight of evidence in favor of the opinion which 

 I originally expressed, for the cranial structure displays Bird-like char- 

 acteristics, as well as does that of the posterior limbs. I have addi- 

 tional evidence bearing on the characters of the pelvis, already discussed 

 by Professors Owen and Huxley, which I will bring forward in a future 

 article. But the existence of a great coronoid process of the dentary 

 bone is an unexpected Mammalian feature, unknown among Birds and 

 Eeptiles, and confirmatory of Professor Owen's assertion of affinities to the 

 Mammalia. The dentary, according to this learned author, takes part 

 in such a process in Iguanodon anglicus^ but to a small degree in com- 

 parison with what is seen in the Judith Kiver Binosauria. 



The complex dentition, embracing such an enormous number of dis- 

 tinct pieces in the herbivorous genera, represents the highest develop- 

 ment of this part of Eeptilian organization. As already remarked, the 

 separate teeth in some species of Bicloniiis was over seven hundred ; in 

 Cionodon arctatus of the Colorado Lignite, should the number of dental 

 columns be as great as in the first-named form,' the total number of teeth 

 would be about two thousand, since they are more numerous in the 

 transverse direction. 



* In Contributions to the History of the Vertebrates of Mesozoic Periods iu New 

 Jersey and Pennsylvania, Proc. Acad. Nat. Sci. Phila., 18G7, p. 74, (May), of which an 

 abstract is given, loo. cit., 1867, p. 234. 



