21 8 ABSTRACTS 



Age of the Lower Coals of Henry County, Missouri. By David White. 



Under this title was presented a discussion of the evidence derived 

 from extensive collections of fossil plants as to the stage of those coals 

 in other American and European sections. Although the stratigraphic 

 palseobotany of the Pennsylvania-Ohio bituminous series is but very 

 imperfectly known, the indicated position of the basal coals of Henry 

 county is apparently higher than the Mazon Creek stage or Brookville 

 and Clarion coals, and presumably lower than the Middle Kittanning, it 

 being perhaps near the Lower Kittanning in that series. Compared with 

 the plants from the section of the Northern anthracite field the Missouri 

 flora is considered by Mr. White as hardly so recent as the E ("Pitts- 

 ton" or "Big") vein though probably as late as the D ("Marcy") vein 

 with which it seems to be nearly synchronous. 



Concerning the relations of the Missouri flora to the floras of the 

 Old World, to which forty-two of the fori"y-four American genera are 

 common, the conclusions are very interesting if, as the author main- 

 tains, the occurrence of the same species in the different basins was 

 approximately contemporaneous. The comparative studv of the geo- 

 graphical and the vertical distribution of the species from the basal 

 coals of Henry county shows that this flora is probably later than the 

 Middle Coal Measures of Great Britain, the closest alliance being with 

 that found in the "transition series" between the Middle Coal Measures 

 and the Upper Coal Measures, with the flora of which ours has much 

 in common. A similar strikingly intimate relationship, involving a 

 large percentage of identical species, exists between the Henry county 

 flora and that of the Valenciennes series {Houiller Moyen) in the Franco- 

 Belgian field. The American flora is clearly not older than the third 

 or upper zone of this series, to which M. Zeiller would also refer our 

 Mazon Creek plants. The correlative conclusions respecting the Brit- 

 ish and the Franco-Belgian measures are corroborated by the relations 

 of our flora to the plants of the Geislautern beds, which shows that the 

 stage of the Missouri plants is in the upper part, probably near the top 

 of the Sarrbrucker Schichten (Westphalian). 



The local stratigraphic position of the phytiferous beds of Henry 

 county, the Jordan coal, and another seam about forty-five feet higher, 

 is, as described in the state reports, somewhat peculiar, since these beds 

 lie, at some points, in almost direct contact with the deeply eroded 

 floor of Mississippian rocks. The plants offer therefore criteria by 

 which to approximately fix the date when the early Meso-Carboniferous. 



