114 THE POTOMAC OR YOUNGER MESOZOIC FLORA. 



upper surface the auricles at the base of the phmules overlap more or less 

 the surface of the maiu rachis. 



Angiopteridium nervosum, sp. nov. 



Plate XXIX, Fig. 2. 



Froud unknown ; pinnules seen only in fragments, but apparently 

 long, 3. 5*"" wide; midnerve comparatively very slender; leaf-substance 

 comparatively thin; lateral nerves slender but distinct, going off at an 

 angle of over 45'', arched backwards slightly for a short distance from tlie 

 midrib, and then inclined forward towards the tip of the pinnules; simple 

 or forking at various distances between the midrib and margin. 



Locality: Fredericksburg; rare. 



This plant was found in only a few small fragments. The nerves on 

 the right-hand half of the figure are distorted by pressure. They are 

 shown in their normal position in the left-hand half. It is something like 

 Tceniopteris Stenoneura Schenk,' and also Tceniopteris tenuinervis Brauns, 

 as given in Figs. 3, 4, of the same plate, but it is larger than either, and 

 has the nerves more dichotomous than the last. It is also a little like 

 Tceniopteris vittata Brongn. It has nearly the nervation of Angiopteridium 

 McCldlandi of the Indian flora. 



Angiopteridium ellipticum, sp. nov. 



Plate XXIX, Fig. 3. 



Frond unknown ; pinnules elliptical, length, 37™", maximum width 

 15°""; leaf-substance membranaceous; midnerve comparatively very stout ; 

 lateral nerves slender but very distinct, going off at an acute angle and 

 then obliquely ascending to the margin, mostly forked at or near the base, 

 branches simple and nearly parallel. 



Locality: Fredericksburg; only one sjDecimen found. 



This is a very distinct but unusually small plant. It seems to be 

 nearer to Stangerites ensis Oldham and Morris, than any other. This has 

 been made an Angiopteridium by Schimper. Possibly this may be a young 

 leaf of some of the species described under another name in the Potomac 

 flora. 



' Foss. Flor. der Grenzschichten, PI. XXV, Fig. 5. 



