224 Systematic Paleontology 



It is difficult to see what evidence, unless it be the supposed relation- 

 ship with the modern Rhipidopteris, led Fontaine to claim a creeping- 

 habit for these forms. The rachis is sometimes more or less flexuous, 

 but not markedly so, and the length is relatively great. Proximally, 

 however, the rachis becomes stouter with decompound pinnae as broad 

 or broader than they are long. It seems probable that this form was not 

 a ground dweller with creeping rachis or rhizome, nor did it adhere to 

 tree trunks, but reclined or clambered over the abundant erect Lower 

 Cretaceous vegetation, as does the modern Lygodium. It appears to be 

 closely related to Sphenopteris dehilior Sap.^ of the Albian of Portugal. 



Occurrence. — Patapsco Formation. Near Wellhams, Federal Hill 

 (Baltimore), Maryland. Near Brooke, 72d milepost, Hell Hole, Mouth 

 of Hell Hole (?), White House Bluff, Dumfries Landing, Aquia Creek 

 Cut, and Mt. Vernon, Virginia. 



Collections. — IJ. S, National Museum, Johns Hopkins University, 

 Goucher College. 



AcROSTiOHOPTERis ADiANTiFOLiA (Fontaine) Berry 

 Plate XXIV, Figs. 2, 3 



Baieropsis adiantifoUa Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 



1889, p. 211, pi. xcii, figs. 8, 9; pi. xciii, figs. 1-3; pi. xciv, figs. 2, 3. 

 Baieropsis adiantifoUa Fontaine, 1899, in Ward, 19tli Ann. Rept, U. S. Geol. 



Survey, pt. ii, p. 684, pi. clxviii, fig. 8. 

 Baieropsis adiantifoUa Fontaine, 1906, in Ward, Mon. U. S. Geol. Survey, 



vol. xlviii, 1905, pp. 510, 528, 538. 

 AcrosticJiopteris adiantifoUa Berry, 1910, Proc. U. S. Natl. Mus., vol. 



xxxviii, p. 629. 



Description. — "Stems moderately strong; leaves subopposite to oppo- 

 site, closely placed, often imbricated, subquadrilateral to flabellate fan 

 shaped, narrowed to a wedge-shaped base, and attached by a short pedicel 

 which springs from the lower corner of the leaf, so that the inner margin 

 of the leaves runs close to the main stem, parallel with it, and often 

 overlapping it, while the lower margin of the leaves stands nearly at 



^ Saporta, Fl. Foss., Portugal, 1894, p. 161, pi. xxviii, figs. 5, 5a. 



