628 PROCEEDINGS OF THE \ \TI<>\ \l UUSEl I/. vol 38. 



Baieropsis foliosa Fontaine, Monogr. U. S. Geol. Surv., No. 15, 1890, p. 209, 



pi. 93, figs. 4-6. — Fontaine, in Ward, Mmiu^r. U. S. Geol. Surv., No. 48, 



L905, pp. 481, 182, 489, 504, 508, pi. 110, fig. 9. 

 Buicmpsis denticit/aiu anguslifolia Fontaine, Monogr. U. S. Geol. Surv., No. 



L5, 1890, ]>. 210, pi. Hi', fig. 7.— Fontaine, in Waed, Monogr. U. S. Geol. 



Surv., No. 48, 1905, p. 491. 



Description. — Frond- with relatively Long pinnae, decompound 

 proximad and becoming simpler distad, the ultimate pinnules sub- 

 opposite to alternate, rather close set. Pinnules inequilateral and 

 slightly decurrent, cut into several narrow sublinear divisions and 



terminated by two or more subacute teeth. The lower pinnules are 

 wider and more laciniate and more decidedly alternate on the stout 

 rachis. Venation line, but distinct, flabellate and dichotomous, ulti- 

 mate divisions terminating in the apical teeth. The sterile and 

 smaller specimens tend to much greater density than those of larger 

 size or those showing traces of fructifications. The fructifications, 

 which are illy defined in the coarse matrix, are borne on the proximal 

 or distal or both basal segments of the pinnules; the segment or seg- 

 ments involved become wider and shorter and elliptical in outline. 

 No details can he made out. 



This species is exceedingly common in the Patapsco formation to 

 which it is confined, being especially common in the beds of this age 

 at Federal Hill, to which locality it is largely confined in the Mary- 

 land area. In Virginia it occurs at a large number of localities 

 within this formation. 



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

 relation 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 nol 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 SpJienopteris 

 debilior Saporta a of the Albien of Portugal. 



Occurrence. Patapsco formation. Near Wellhams, Federal Hill, 

 Maryland. Near Brooke, 72d milepost, Hell Hole. Mouth of Hell 

 Hole?, White House Bluff, Dumfries Landing, Aquia Creek cut, and 

 Mount Vernon. Virginia. 



Collections. U. S. National Museum. Johns Hopkins l'ni\ ersit \ . 



aporta, Flora Fobs. Portugal, L894, p. L61, pi. 28, Bga 5, 5a. 



