Maryland Geological Survey 463 



While the Potomac species have the characteristic peltate leaves they 

 are not radially symmetrical as are the later species but have the petiole 

 attached nearer to one margin giving them an appearance much like 

 that of a number of supposed species of Menispermites. The venation 

 is, however, nearer that of Nelumbo and its allies, the secondaries being 

 prominent on the lower surface, obsolete on the upper surface, and fork- 

 ing after the manner of the Nymphgeaceee. If these leaves were not 

 floating it is surprising that a petiole stout enough to hold the leaf erect 

 is not found fossil, unless the leaf normally abscissed from the apex in- 

 stead of the base of the petiole. It is hoped that sooner or later specimens 

 will be found showing whether or not the stomata were confined to the 

 upper surface and thus confirming or disproving the assumption here 

 made that they were aquatic in habit. 



The author has followed Fontaine in keeping the two following species 

 separate, although they are very similar except as to size and the resulting 

 calibre of venation, and it would have done little violence to the facts 

 to have united them in a single species. They are characteristic forms 

 of the Patapsco formation and quite abundant at certain outcrops. The 

 existing species of Nelumbo are two in number, both large aquatic 

 perennials, one North American and the other Asiatic and Australian. 

 It has seemed better to establish a new genus for the reception of these 

 older Cretaceous forms, which while expressing their proper affinities 

 does not unduly extend our conception of the modern genus. 



It is interesting to note in this connection that Saporta '^ has reported 

 two species of Nelumhium from the supposed Albian of Portugal, but as 

 these are not fully defined and unfigured their relation to the following 

 American species is unknown. 



Nelumbites virgin iensis (Fontaine) Berry, 

 Plate LXXXII, Pigs. 3-5 



Menispermites virginiensis Fontaine, 1890, Mon. tt S- Geol. Surv., 1889, 

 vol. XV, p. 321, pi. clxi, figs. 1-2. 



^ Saporta, Comptes rendus, tome cxix. 1894, pp. 835-837. 

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