A REVISION OF THE FOSSIL PLANTS OF THE GENUS 



NAGEIOPSIS OF FONTAINE. 



By Edward W. Berry, 



Of the Johns Hopkins University, Baltimore. 



In the elaboration of the Potomac flora of Maryland for the pro- 

 posed monograph of the Maryland Geological .Survey it has been 

 found necessary to reexamine all of the Virginia material and in 

 many eases to recast certain of the larger genera where the limits 

 have been found to be vague. That the multiplication of species 

 in the past has been much greater than the facts warranted has long 

 been suspected, and several writers, notably Seward, have voiced 

 this view. A careful study only serves to emphasize this opinion, 

 and it is proposed to publish several of these systematic revisions 

 as fast as they are prepared, since the proposed monograph deals 

 mainly with species known to occur in Maryland. Furthermore, 

 the Patuxent formation, the basal member of the Potomac group, 

 is extremely deficient in plant remains in the Maryland area, while 

 a representative flora is present at this horizon in Virginia, so that 

 generic revisions lack balance unless the full data which form the 

 foundation of the new interpretations are given. 



The writer has had the advantage of studying at one time all of 

 the specimens collected by Fontaine, Ward, Bibbins, and others, 

 and this method has served to disclose certain errors of identifica- 

 tion which resulted from the method of the former, who worked over 

 a long period of years upon collections from a large number of locali- 

 ties and without the various types at hand for comparison. The 

 writer is under obligations to the l T . S. National Museum, where all 

 of the Potomac types are lodged, for many courtesies, and he also 

 gratefully acknowledges the constant advice and criticism of Dr. 

 F. II. Knowlton. 



The first genus to be considered is Nageiopsis, which was founded 

 by Fontaine in 1890, for forms apparently allied to the modern 

 species which make up the Nageia section of the genus Podocarpus. 

 lie characterizes Nageiopsis as follows: 



Trees or shrubs with leaves and branches spreading in one plane; leaves varying 

 much in si/.e and shape, those toward the base of the twigs sometimes smaller than 

 those higher up, distichous mostly, or rarely subdistichous, opposite and persistent, 



Proceedings U. S National Museum, Vol. 38— No. 1738. 



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