FLORA OF THE GREEN RIVER GROUP. 201 



ence of 40° on the right side, a little more open on the left, ascending high 

 and reticulate along the borders; the areolation is formed of nervilles at 

 light angles, forking or anastomosing in the middle of the areas, rarely 

 simple. 



These leaves only differ from the one described by Heer under this 

 name in their slightly larger size and in the apex being a little more deeply 

 emarginate. The nervation is peculiar and evidently of the same type as 

 in the European leaves, where the lateral nerves are, however, somewhat 

 obsolete. The secondary nerves, four pairs, are distant, alternate, the 

 upper pairs curving inward toward the apex of the midrib. 



Hal. — Florissant. Princeton Museum, Nos. 790, 791. 



CERCIS, Linn. 



Cercis parvi folia, ep. nov. 



Plate XXXI, Figs. 5-7. 



Leaves small, membranaceous, round or subtruncate at base, broadly cuneate to 

 the slightly-pointed apex, very entire, five-nerved at base; medial nerve slightly 

 stronger, secondary nerves camptodrome. 



The three leaves figured and a few others seen in the shale of Floris- 

 sant are small comparatively to those of this genus described as fossil. 

 They are equilateral, enlarged, and truncate or subcordate at base; the 

 basilar nerves are at right angles; the lateral at an angle of divergence of 

 30° to 40° are camptodrome like their divisions. The reticulation is obsolete. 

 None of the few fossil species of this genus are comparable to this. The 

 leaves vary from li to 3 centimeters in width, being as long as broad. 



Hal.— Florissant. Princeton Museum, Nos. 766, 767, Figs. 5 and 6; 

 the other from the U. S. Geol. Expl. Dr. F. V. Harden. 



P0D0G0NIUM, Heer. 



* U. S. Geol. Rep.," vii, p. 298. 



Po do go n iu in acuminatum, sp. nov. 

 Plate XL, Fig. 9. 



Leaflets sessile, subcoriaceous, very entire, oblong, obtusely acuminate, narrowed 

 to a short petiole, slightly unequilateral at base; lateral nerves close together, very 

 open or nearly at right angles to the midrib, curved, camptodrome; tertiary nerves 

 parallel, as long as the secondary, thin. 



