400 AV. D. MATTHEW THE CRJ:TACE0US-TERTIARY PROBLEM 



floras; that the asserted magnitude of the break between Laramie and 

 Lance rests not on evidence, but on a definition of the Laramie (see 

 Appendix B), and that no really adequate evidence has been adduced of 

 its relations to the Cretacic-Tertiarv break in Europe. The ])aleobotanic 

 argument for placing- the Lance in the Tertiary is the resemblance of its 

 flora to that of the Paleocene and its great difl'erence from tliat of the 

 true Ivaramie. But there is no evidence that the Lance flora was absent 

 from Europe in the hite Cretaceous, and the Laramie clearly represents 

 a different facies from the Lance. Doctor Knowlton has insisted strongly 

 on the entire absence of dinosaurs in the true r^aramie. a])])arently with 

 the idea that il sliowed it to be niucli older than the Lance. But as the 

 same phyla of dinosaurs are present in the older Belly River and in the 

 newer Lance, their absence from the Laramie is obviously due to a dif- 

 ference in environmental conditions. The facies of the fauna is different 

 and much, if not all, of the difference in flora should be ascribed to this 

 cause. 



For these and many other reasons, the evidence summarized by Doctor 

 Knowlton in favor of transferring the Lance and associated formations 

 to the Tertiary appears to me inconclusive, and it is directly in conflict 

 with the evidence from fossil vertebrates, so far as I am able to under- 

 stand it. But in view of this conflict, real or apparent, I do not regard 

 the problem as a settled one LTntil all the data have been brought into, 

 conformity and the exact position of the principal diastrophic break con- 

 clusively shown from more convincing data than are at present available, 

 it seems to me better to hold to the current classification, which is at least 

 supported by evidence better, in my opinion, than any that has been 

 brought forward in favor of Doctor Knowlton's views. 



AlMMOXDIX A. AmJ-OKD OccriJKKXCKS OF DlXOSAllfS IX Ti:ktiai{Y 



EoifMATIOXS 



Doctor Knowlton has asserted that dinosaurs do occui- in the Fort 

 Union foi'ination. 'I'he evidence, as far as 1 am acquainted with it, is 

 tliat dinosaur I'eniains have been found sonic hundreds of feet above an 

 arbitrary line taken as the line of sei)aration between l>aiu*e and Fort 

 Union. They have not been found associated with Paleocene vei'tebrates : 

 nor are they known to be ditferent from the dinosaurs of the l^ance beds 

 l)eneath them. Fossil ])lants if found associated would give no trust- 

 worthy evidence, since the fioras of the Lance and Fort Union are ahnost 

 identical, most of the species being common to the two. The obvious 

 inference would he that the dixidiiiii- line, confessedlv arbitrarv, was 



