106 Remarks on the Cretaceous and [February, 



species which can be pointed out as indicating a distinct relation to 

 plants of the Laramie group. Leaves of Cinnamomum have been 

 described by Dr. Newberry from the Orcas island (Descriptions of 

 fossil plants collected by Mr. G. Gibbs) and supposed by the 

 author to be referable, partly at least, to Cinnamomum Heerii, de- 

 scribed first from Vancouver's island. The author's remark, that 

 the specimens, though typically allied to Cinnamomum Schaich- 

 zeri and C. lanceolatum, indicate a larger and thicker leaf, confirms 

 his supposition ; for Cinnamomum Heerii, of which a fine specimen, 

 preserved entire, has been obtained this year in Kansas for the 

 Museum of Comparative Zoology of Cambridge, merely differs 

 from C. affine, found at Golden and Carbon, by its more rounded 

 base, both species being represented by leaves equally large and 

 subcoriaceous. This form, therefore, passes to the Miocene 

 through the Eocene without apparent modification. Of smaller 

 leaves described from specimens of the Dakota group as Cinna- 

 momum Scheuchzcri, a species of which two fine specimens have 

 been also procured this year in Kansas, none have been seen in the 

 plants of the Lignitic. The ferns of the last group also are without 

 analogy to those published by Heer and myself from the Dakota 

 group. The same can be said of the conifers, except Abietites 

 dubius, which according to Saporta,has,by the scars left by the base 

 of the leaves upon the stems, some analogy with Cunninghamites, 

 a Cretaceous type. In the monocotyledonous, the palms especially, 

 in the angiosperms the types of Populus, Platanus, Quercus, 

 Ficus, Laurus, Viburnum, Rhamnus, Juglans, etc., all appear 

 without relation to any of those of the Dakota group. Per con- 

 tra, when comparing the plants of this Cretaceous formation with 

 those of the Miocene of Carbon, even of the Pliocene of Califor- 

 nia, we find closely allied types, even identity of characters in 

 species of Salix and still more in those of Populus. For exam- 

 ple, between Populus elliptica Newby., Illustr. of species, PI. Ill, t 

 1-2, of the Dakota group, and P. cuneaia Newby., ibid., PI. xiv, f. 

 1-4, of the Union group, no possible difference is found in the 

 shape, size and nervation of the leaves. In the Cretaceous spe- 

 cies, the borders are a little more distinctly crenate-serrate. But 

 such a difference is of no account in leaves of the same type as 

 the polymorphous Populus arctica, whose borders are entire or 

 undulate, or more or less deeply serrate-crenate. Liriodendron 

 and sassafras, not at all represented in the Laramie, are found in 



