398 MESOZOIC FLORAS OF UNITED STATES. 



series. Indeed, Professor Fontaine now places the Federal Hill beds 

 in Baltimore, formerly regarded as representing the Brooke series, in 

 the Rappahannock, and finds no true Brooke flora anywhere in Mary- 

 land except at Hosiers Bluff, above Fort Foote, on the Potomac, which 

 seems to be a simple continuation of the beds at White House Bluff, 

 across the river. 



The Patapsco is therefore not a paleontological division, and the 

 number of plant-bearing beds of which the position is regarded as doubt- 

 ful shows that the authors are far from knowing the characteristic marks 

 by which it can be recognized with certainty. After visiting nearly 

 all their sections I have arrived at the conclusion that none such exist. 



The Raritan formation is synonymous with what I called the 

 Albirupean of Uhler. I understood him to limit it to the upper clays 

 and sands yielding a chiefly dicotyledonous flora. Professor Uhler has 

 since so greatly expanded his conception of the Albirupean that it is 

 difficult to retain his name, and as the name Raritan was very early 

 applied to most of the clays of New Jersey, that name may be regarded 

 as having priority over all other names that admit of use as designations 

 for a heterogeneous formation. 



Influenced by "the distinguished authority of Professor Marsh," 

 the authors of this paper provisionally refer the Patuxent and Arundel 

 formations to the Jurassic, and in their comparative taxonomic table, 

 on page 505, they place the former of these below any of the Virginia 

 beds, all of which they include in the Cretaceous. 



In Science of August 5, 1898, and in the American Journal of Sci- 

 ence for August of that year. Professor Marsh published a "Supplement" 

 to his paper already considered on The Jurassic Formation on the Atlan- 

 tic Coast, in which he replied to the various articles that had appeared 

 criticising his position. He had, however, discovered no further evi- 

 dence. He was then in possession of many trunks of cycads from the 

 Black Hills, and he also referred the beds from which they came to 

 the Jurassic, although they were found in the sandstones of the "rim" 

 which had all along been called "Dakota group," and so regarded even 

 by himself in various sections that he had made. I had found a flora 

 below the cycad horizon that proved the whole to be Lower Cretaceous. 

 But Professor Marsh had also received specimens of cycads from the 



