FLORA OF THE DAKOTA GROTTP. 85 



todrome, follow close to the borders, the lower pair at a more acute angle 

 of divergence as marginal veins, and those of the middle abruptly curved, 

 following also close to the borders with the same appearance as that of 

 the basilar nerves. This nervation is related to that of some species of 

 3Iynca, and still more of Ilex, like /. Ahichi, I. herheridifolia, Heer, of the 

 Miocene. The areolation, distinct only on a small area where the epidermis 

 is destroyed, is in small, angular or irregularly square areoles. The nar- 

 rowing of the leaf in the middle appears as produced by the gnawing of 

 insects. But if the vein which follows the border is not a deceptive repre- 

 sentation caused by the thickness of the leaf, this peculiar deformation is 

 natural. Leaves of Ilex are often variously and abnormally cut. 



Hab. — Same as I)ryoi)liyllum (QuercusJ Holmesii, in connection with 

 coal strata of Southwest Colorado at a higher stage of the Cretaceous. 

 H. Holmes. 



FEANGULACE^. 



PALIURUS, Toum. 



Paliurus niembranaceus, Lesqx. 



"U. S. Geol. Rep.," vi, p. 108, pi. xx, fig. 6. 



RHAMNUS, Jnss. 

 Rhamnus tenax, Lesqz. 



"U. S. Oeol.Rep.," vi, p. 109, pi. xxi, fig. 4. 



Rhamnus prunifoliu.s, sp. nov. 



Leaf coriaceous, ovate-lanceolate, rounded in narrowing to the base; medial 

 nerve deep, straight; lateral nerves at short distance, parallel, open, arched in jjassing 

 toward the borders and curving along and close to them ; nervilles close, numerous, 

 oblique to the nerves. 



This leaf, 4 to 5 centimeters long (point broken), nearly 3 centimeters 

 in the middle, resembles what Heer describes as Salix nermllosa, "Phyll. 

 Cr6t. du Neb.," pi. i, fig. 3; but the lateral nerves are open, joining the 

 medial nerve nearly at right angles, parallel from the base of the leaf, which 

 is not cuneiform but more rounded; the nervilles are oblique to the veins. 

 The nervation is that of a Ehamnus. 



Hab. — Near Glasco, Kansas. Chs. Sternberg. No. 479 of the Museum 

 Comp, Zool., Cambridge. 



