210 W. D. Mattheiv — Fossil Vertebrates and 



Professor Parks,^ the major part unpublished. Mr. 

 Gidley is still engaged upon the important mammal fauna 

 of the Fort Union, but a portion of his researches are 

 published and available. Dr. Schlosser has recently 

 described^ and illustrated a small collection of Cernaysian 

 fossils in Berlin Museum, and discussed their affin- 

 ities and geological correlation. Finally, but not least 

 in importance, M. Teilhard de Chardin has been engaged 

 upon a very able and thorough revision of the Paleocene 

 and Lower Eocene mammal faunas of the Paris basin 

 and has published a brief resume of his conclusions.^^ 



Characteristics of Late Cretaceous Vertebrate Faunas. 



In summarizing the vertebrate evidence it will perhaps 

 be best to begin with the faunas above and below those in 

 dispute, whose position in the Cretaceous and Tertiary 

 respectively is beyond question. 



1. The Judith or Belly River formation on the Red 

 Deer Eiver, Alberta, lies conformably beneath the upper 

 part of the marine Upper Cretaceous Fort Pierre. Its 

 position in the Cretaceous is undisputed. It is equivalent 

 to a part of the Upper Senonian chalk of "Western Europe 

 Upper Cretaceous but by no means at the end of the 

 conformable Cretaceous succession, as it is followed by 

 the Maestrichtian and Danian divisions of the chalk 

 representing a long period of time. It contains a 

 splendidly preserved vertebrate fauna. 



2. The Wasatch formations in Wyoming, New Mexico 

 and elsewhere contain a vertebrate fauna of Suessonian, 

 Lower Eocene, age, corresponding and very closely 

 related to the fauna of the Argile plastique of the Paris 

 basin and the London Clay of England. They have 

 yielded a very large and varied mammalian fauna, and 

 some reptiles, etc. 



Between these two undisputed horizons lie the for- 

 mations under discussion. They belong either just above 

 or just below the boundary line, a line whose precise 

 position must be fixed either by precedent or by agree- 

 ment. 



« Parks, 1920, Univ. Toronto Stud., Geol. Ser., No. 11, pp. 1-76. 

 » Schlosser 1921, Palseontographica, LXIII, pp. 97-144, 2 pi. 

 ^° Comptes Eendus, Dec. 6, 1920, pp. 1161-1162. 



