142 CONTRIBUTIONS TO PAL^ONTOLOGY 



not known to occur in "Fort Union" sediments or other formations of undisputed Paleocene or 

 later age. 



The reference of this species to the existing genus Nelumbo seems rather certain; no other 

 modern leaves have come to my attention which have the combination of features observed in the 

 fossil forms. 



Occurrence — U. S. Geol. Survey Locality 1485. 



Collection — U. S. National Museum, No. 40253. 



Genus NYMPH^ITES Sternberg 



Nymphseites browni Dorf, n. sp. 



(Plate 10, Fig. 9) 



The figured specimen, and one othor from the coUections of the U. S. National Museum, are 

 the only ones of this kind encountered. 



Description — Leaf cordate-orbicular, about 3.5-4 cm. in diameter, with entire margin and 

 deeply cordate base; veins radiating from base, about 14 in number, irregularly forking acutely 

 toward the margin, usually twice or three times; tertiary venation not preserved; texture appar- 

 ently fairly thick. 



This species, which differs mainly in its well-defined cordate base from the other species of 

 Nymphseacese in the Lance flora, is comparable in some of its characters to Castalial dxdtoniana 

 Knowlton ' from the Mesaverde formation of southeastern W.yoming. The deeply cordate base, 

 however, clearly distingui.shcs it from that species as well as other fossil species. Its modern 

 relationship is clearly with the Nj^mphseacese. 



The species is named for Dr. Roland W. Brown, of the U. S. Geological Survey. 



Occurrence — U. S. Geol. Survey Locality 1462. 



Collection — U. S. National Museum, Cotypes Nos. 40254, 40255. 



Nymphaeites dawsoni (Holllck) Dorf, n. comb. 

 (Plate 10, Figs. 6-8) 



Nelumhn dawsoni HoIIiok, Bull. Torrcy Bot. Club, vol. 21, 309, 1894. Berry, Canada Geol. Surv. Mem. 182, 

 36, pl. 7, fig. 1, 1935. Brown, U. S. Geol. Surv. Prof. Paper 189, 250, pl. 48, fig. 11, 1939. Dorf, Bull. 

 Geol. Soc. Amer., vol. 51, 218, 222, 225, 1940. 



Brascnia anliqua Newberry. Dawson, Trans. Roy. Soc. Canada, vol. 3, sec. 4, 15, text fig., 1886. 



Lemna scutala Dawson. I^squereux, Rept. U. S. Geol. Surv. Terr., vol. 7, 102, pl. 61, fig. 2 only, 1878. 



Nelumho laramiensis HoIIick, Bull. Torrey Bot. Club, vol. 21, 307, text fig., 1894. 



Nelumho inUrmedia Knowlton, U. S. Geol. Surv. Bull. 163, 53, pl. 13, figs. 3-5, 1900. 



The 3 specimens figured are the best of 6 impressions of this leaf form in the collections. 

 These cannot be distinguished on any valid, natural basis from the figured or type specimens of 

 the several species listed above. 



In their discus.sions of Nelumbo daicsoni, both Berry and Brown united all the above species 

 into one, on the basis of vaHd resemblances in essential details. No other leaves of comparable 

 size and characteristics havo been reportcd from the Mesozoic or Ccnozoic of North America. 

 The species is at present known in the upper Mesaverde, Belly River, Vermejo, Whitemud, 

 Colgate, and type Lance floras. It is not reported from anj'^ deposits of known Paleocene or later 

 age. 



As was intimated by Berry, the generic reference of this species to Nelumbo is doubtful. I 

 have not seen any leaves of modern species of Nehanbo which are comparablc with the fossil 

 specimenseitherinsizeorinaverage number of secondary veins. Theleaves of theliving Brasenia, 

 on the other hand, are more nearly similar; see, for example, Brascnia ppltata Pursh. In view of 

 the general resemblance of the fo.ssil specics to several gencra of the Nympha-acese, it seems ad- 

 visable to refer it to the genus Nymphseites, implying family relationship only. 



Occurrence — Locality P3853. 



Collection—\J. C. Mus. Pal., Plesiotypes Nos. 2516, 2517, 2518. 



' Knowlton. F. H.. U. S. Gcol. Surv. BuU. 163, 65, pl. 13, fig. 7. 1900. 



