580 MESOZOK' FLORAS OF l^MTEL) STATES. 



A stratum at Dutch (Jaj) m Vii-giuia, where this phiut was first found, 

 is full of multitudes of small fragments of it, each representing one or two 

 joints. I was in great doubt as to the true place of the fossil he named 

 PagiophyUum dubium, and with much hesitation placed it provisionally 

 in tlie genus PagiophyUum. He did not think the amount of material 

 on hand justified the formation of a new genus. As this plant j)rol)al)ly 

 is not a PagiophyUum. it may well continue to hear the name given it 

 by Doctor Xathorst, and the name Pa(/io]>hyUum duhhim should be 

 dropped. It should not, however, l^e identified with Frcnelopsis parce- 

 ramosa. A plant nearly allied to the latter, but })i'obably a different 

 species, occurs in the (Hen Rose strata. 



CORRELATIOS OF THE POTOMAC FORMATIoX IX VIKGIMA AXU MARY LAX D. 



The above report of Professor Fontaine on the fossil plants collected 

 in the Potomac formation since the appearance in 1889 of his Potomac 

 or Younger Mesozoic Flora furnishes a much better Ixisis for correlating 

 the ^laryland and Virginia beds of that formation than that which existed 

 at that time or at the later date (1895) when my memoir on the Potomac 

 formation appeared. In order, however, still more fully to appreciate 

 the advance thus made in oui- knowledge of the flora in the two States, 

 and to fiu-nish a condensed view of the results, 1 have prepared the fol- 

 lowing table of distribution of the species enumerated in the report : 



