DESCRIPTION OV THE SPECIES. 73 



Jurassic ferns from widely separated portions of tlie glolje. Among these 

 we have Ncuropfcris rercntior, L. and II., Foss. Flor. of Great Britain, IM. 

 LXVIII, and several of the fossils nniti'd h}' Heer with Asplniium Wltithi- 

 cnsis, in his article on the Jnra. Flor. Ost. Sil)., Flor. Fos.s. Arctica, vol. 4, 

 No. 2, p. t»4, Pccoptcy'ia Tiidica of Oldham and Jforris, and Nathorst's figures 

 of Cladophlebis nehhcnsis from the Rluvtic of Sweden, resemble in some 

 points the smaller forms of the Potomac plant. Some of the pinnules of 

 C. nehhcnsis show a fine toothing similar to that found on ChuhpMchls 

 dent kid at a. 



I have with some hesitation grouped under the species C. fidcata sev- 

 eral forms that do not reseml)le in all respects the more common and typ- 

 ical specimens of that species, wliich may be taken as represented in PI. V, 

 Figs. 1, 2. The bluntly terminated pinnules in PI. V, Figs. 3, 5, also the 

 ver}' sliglitly falcate pinnules and the nerves of PI. VII, Fig. 2, show a 

 dejjarture from the normal form. 



Cladophlebis parva, sp. nov. 



Plato IV, Fig. 7; Plato VI, Figs. \-X 



Frond 1)ipiniiate or trij)innate; principal rachis proportionally very 

 stout and rigid; pinn:v .short, alternate to subopposite; pinnules alternate, 

 ovate, subfalcate, acute, excejit in the upper part of the frond, separate to 

 the base; midnerve as in the genus; lateral nerves mostly once forked; 

 leaf-substance thick. 



Locality: Fredericksburg; rare. 



In the shape of its piniudes it belongs to the sanie type as ('. Vir(//»i- 

 ensi'i, but tlie nerves are not so copiouslv l)ranclied towards the base of the 

 pinnules, and do not diminish in the number of branches so rapidh' towards 

 the sunmiit of the pinnules. It is much like Cladopldehis pseiidowhit- 

 hiensis,^ but is a smaller plant. It resembles also the upper part of Pecop- 

 teris dentafa, given by Lindley and Hutton in Foss. Flor. of Great Britain, 

 PI. CIvXIX. The nerves, however, do not agree with those of that plant. 



This small fern is j)rol)ably another survivor of the Jurassic, or ratlun- 

 Rhajtic, flora of Virginia. 



'Contributions to the Knowledge of the Older Mcsozoic Flora of Virginia: U. S. Geol. Survey, 

 Men. No. G, ljj-^3, p. 52, PI. XXVII, Fig. 4. 



