498 . Systematic Paleontology 



unknown, for while they may be compared with a number of modern 

 plants, they present no characters entitled to any great weight, certainly 

 they do not furnish adequate evidence of their angiospermous nature, 

 although they may well be the remote representatives of this type since 

 there are no grounds, theoretical or otherwise, to deny the existence of 

 angiosperms at such a relatively late date in the Mesozoic. 



The genus Protecephyllum of Fontaine must not be confused with 

 ProtopJiyllum Lesquereux (Cret. FL, 1874, p. 100) or Proteophyllum 

 Velenovsky (Kvetena ceskeho cenomanu, 1889, p. 18). Saporta has 

 referred a number of Portuguese Lower Cretaceous forms to the latter 

 genus, which is supposed to be related to the existing Proteaceas. 



Proteophyllum renif.oeme Fontaine 



ProtecBphyllum reniforme Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 



1889, p. 282, pi. cxxxix, fig. 3; pi. clvi, fig. 4; pi. clx, figs. 1, 2 (non 



Ward, 1895 or 1896, or Fontaine in "Ward, 1906). 

 Protecephyllum or'biculare Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 



1889, p. 283, pi. cxxxix, fig. 4. 

 PhylUtes pachyphyllus Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 



1889, p. 325, pi. cxlix, fig. 2, 



Description. — Leaves of medium size, reniform to orbicular in out- 

 line, with entire margin, and coriaceous in texture. Length 3 cm. to 

 6 cm., width 4 cm. to 10 cm. Petiole wide and flat, preserved for a 

 length of 2 cm. in some specimens and at times as much as 5 mm. in 

 width. Primaries numerous, thin, diverging from the top of the 

 petiole, anastomosing irregularly and in a lax manner. 



No material shedding any new light on this singular form has been 

 collected and its affinity remains unknown. The forms described as 

 the species reniforine, or'biculare, and pachyphyllus are obviously identical 

 and the records from post-Patuxent horizons prove to be based upon 

 decidedly different leaves in no wise related to this species. 



Occurrence. — Patuxent Formation. Fredericksburg, near Dutch 

 Gap, Virginia. 



Collection. — IT. S. National Museum. 



