312 THE POTOMAC OR YOUNGER MESOZOIC FLORA. 



This plant is very much like some species of Pojndiis, especially in its 

 petiole, which indicates a tremulous leaf. 



POPULOPHYLLUM CRASSINERVE, sp. nOV. 

 Plate CLVIII, Fig. 4. 



Leaf too fragmentary to make out its shape, but apparently veiy 

 large ; midnerve not much surpassing the size of the lowest primary nerves 

 that go off on each side of it, and which, apparently with the midrib, radi- 

 ate from the base of the leaf; the lowest lateral primaries and the mid- 

 nerve in its upper portion send off very obliquely strong subordinate 

 nerves, which in turn bi'anch, but the further subdivision could not be fol- 

 lowed ; the minor nervation not seen. 



Locality : Deep Bottom ; very rare. 



This leaf differs in the pronounced midnerve and the strong nervation 

 from the other species of the genus. Possibly it may be a different genus, 

 but in general character it is most like Popiilus. 



ULMIPHYLLUM, gen. nov. 



Leaves too imperfectly shown in most cases for the shape to be made 

 out ; midnerve comparatively strong and prominent ; lateral or primary 

 nerves opposite or subopposite, strong, and prominent, proceeding straight 

 and parallel to near the margin. 



The leaves placed under this head belong to only a few species and 

 furnish but few specimens. They have some of the features of Quercus, 

 but are on the whole nearer to Ulmus. 



Ulmiphyllum Bbookense, sp. nov. 



PKate CLV, Fig. 8; Plate CLXIII, Fig. 7. 



Leaves small, oval in shape, subacute ; margins cut into subacute 

 shallow teeth that are mostly double ; midnerve very strong ; lateral 

 primary nerves going off very obliquely, subopposite, directed upwards, 

 nearly straight and parallel in their course to the margin, the basal pair 

 being considerably the strongest and most branched; the primary nerves 



