474 MESOZOIC FLORAS OF UNITED STATES. 



RECENT COLLECTIONS OF FOSSIL PLANTS FROM THE OLDER POTOMAC OF 

 VIRGINIA AND MARYLAND. 



Professor Fontaine's report on all the Potomac material that had 

 been sent to him was received on November 12, 1902. The type speci- 

 mens designated b.y him to be drawn arrived in advance of the report 

 and work upon them was begun in the division of illustrations in 

 December. The report is not a systematic paper like most of those 

 of Professor Fontaine, but simply gives the results of his examination 

 of the numerous collections in his hands. These he treats separately, 

 so that each collection forms a special report. It therefore amounts 

 practically to a series of reports on material from different localities, 

 which are susceptible to an}^ arrangement that may l^e considered most 

 advantageous. As, however, in a number of cases specimens had been 

 collected more than once from the same locality, and sometimes by 

 different collectors who did not always designate it by the same name, 

 and as these also are treated separately, it has been thought best to 

 combine them and to treat all the forms coming from the same locality 

 and formation under one head, irrespective of the date of collection 

 as well as of the particular person who obtained them. As all the speci- 

 mens bear careful labels and marks showing these details, including the 

 proprietorships of the fossils, this will lead to no confusion in the final 

 disposition of the collections. All those representing new species or 

 deserving special treatment or illustration are accompanied by full 

 descriptions of their sources, and due credit is given to the collector and 

 to the institution to which they l^elong. 



As nearly all the specimens in these numerous collections belong 

 to species that have been described and figured in earlier works, chiefly 

 in Professor Fontaine's Potomac or Younger Mesozoic Flora," he usually 

 contents himself with their identification accompanied by references to 

 the original source. Some of the material, however, add somewhat to 

 the knowledge of the rarer species, and where this is the case the speci- 

 mens best showing character^ are figured in this paper. The most 

 important result is the correlation on this the principal paleontological 

 evidence of the new plant-bearing beds, especially of those in Maryland, 

 from which no fossil plants had previousl}^ been reported, with the 



« Monogr. U. S. Geol. Surv., Vol. XV, 1889. 



