652 REPORT OF NATIONAL MUSEUM, 1904. 



by Lesquereux, he would not venture to doubt the truth of his asser- 

 tions regarding- the same, he nevertheless reminded him that: (1) The 

 flora of the Colorado lignite beds had almost nothing in common with 

 that of the European Eocene, in his judgment not a single species and 

 scarcely any genera being common to both; (2) that the tuberculated 

 fucoid (Halymenites), considered by Lesquereux as diagnostic of the 

 Eocene, was really in New Mexico the most characteristic fossil of the 

 Cretaceous; and (3) that, guided by their animal remains, Professors 

 Marsh. Meek, Cope, and Stevenson had all regarded the Colorado 

 lignites as Upper Cretaceous. 



Newberry further contended that in the plant beds which he had 

 himself designated as Miocene the entire aspect of the flora was iden- 

 tical with the Miocene of Europe, and contained a very considerable 

 number of well-marked Miocene species, not one of which deserved to 

 be called Eocene. The lignite plant beds of New Mexico, which he 

 called Cretaceous but which Lesquereux referred to the Tertiary, 

 were for the most part derived from the lower portions of our Creta- 

 ceous scries, and were overlaid by many hundreds of feet of unques- 

 tionable Cretaceous strata in which all the typical Cretaceous forms 

 were represented. 



He further announced the principle that: 



In the absence of any distinctive or unmistakably Eocene plants, if the strata 

 which contain them (the lignite deposits) shall be found to include vertebrates or 

 molusks which have a decidedly Mesozoic aspect, we shall have to include them in 



the Cretaceous system. 



To Lesquereux's claim that the testimony of his 250 species of fossil 

 plants far outweigh that of the Cretaceous mollusks, he rejoined that 

 these plants were probably all distinct from European Cretaceous and 

 Eocene species and had little or no bearing on the question in hand. 

 He acknowledged it was not impossible that the physical condition of 

 the continent may have been such that the Cretaceous age faded grad- 

 ually into the Tertiary, and that consequently some forms of Creta- 

 ceous life might be found interlocking with those of Tertiary age, but 

 of this he demanded proof, and asserted that as yet none such had 

 been found. 



J. J. Stevenson, meeting with these same beds in his work in con- 

 nection with the Wheeler Survey (1874), pronounced in favor of their 

 Upper Cretaceous age. As for the nodose fucoid Halymenites, he 

 agreed with Newberry that it was not indicative of their Eocene age, 

 since it was never found with any but a Cretaceous fauna. Neither 

 was the evidence of the land plants acceptable to him, the materials 

 being mostly single leaves and in a state of preservation showing that 

 they had been blown from trees growing near streams or on the shore, 

 where they were washed into the sea and became associated with at 



