Maryland Geological Survey 309 



again over a vast region drained by the Donetz and the Don. Eecent work 

 by Eussian geologists and paleontologists has disclosed interesting faunal 

 parallels between the Lower and Upper Cretaceous faunas of that country 

 and those of France, England, and Germany. 



Cretaceous outcrops occur over vast areas in central and northern 

 Eussia, culminating in beds of Cenomanian and Turonian age, the higher 

 series being apparently more fully developed in the southern parts of the 

 empire. (Crimea, Moldavia, Bessarabia, Caucasus, etc.) 



A number of fossil plants, since come to be regarded as probably of 

 Upper Cretaceous age, were recorded by Eichwald in 1865. These have 

 been quoted by the writer in his discussion of Lower Cretaceous floras * 

 and need not be republished, since the forms themselves are vague and 

 their stratigraphic position undetermined. 



Eecently Kryshtofovich has announced 2 the discovery of a well pre- 

 served Upper Cretaceous flora in the Ural province. The plants recorded 

 are the following and their age is unquestionably Cenomanian : 



Asplenium dicTcsonianum Heer 



Cissites uralensis Kryshtofovich 



Pinus guenstedtii Heer ? 



Platanus (Credneria) cuneifolia Bronn 



Platanus (Credneria) geinitziana Unger 



Platanus (Credneria) velenovskyana Krasser 



Platanus sp. 



Pteris frigida Heer ? 



Sterculia vinokurovii Kryshtofovich 



Zizyphus dakotensis Lesquereux 



Fossil wood from various horizons including the Cretaceous have been 

 described by Mercklin 3 and more recently by Kremdovskii/ and there 



1 Berry, E. W., Md. Geol. Survey, Lower Cretaceous, 1911, p. 132. 



2 Kryshtofovich, A., Bull. Acad. Imp. Sci. St. Betersb. sfirie vi, 1914, pp. 603- 

 612, 1 pi. 



3 Mercklin, C. B. von, Balasodendrologikon Rossicum. Breisschrift. k. Akad. 

 Wiss. St. Betersb. 1856, 99 pp., 20 pis. 



Sur un echantillon de bois petrifie provenant du gouvernement de 



Rjasan. Bull. Sci. Acad. Imp. Sci., St. Betersb., vol. xxix, 1884, pp. 243-250. 



4 Krendovskii, M. E. Beschreibung fossiler Baume hauptsachlich aus dem 

 Siiden Russlands I, II. Arbeiten Naturf. Gesell. k. TJniv. Charkow, vol. xiii, 

 1880, pp. 263-294, pis. i, ii. 



