228 SYSTEMATIC PALEONTOLOGY 



Genus ULMUS Linne. 



Ulmus betuloides n. sp. 

 Plate LXX, Fig. 1. 



Description. — Leaf oblong-ovate (?) in outline, serrate; secondary 

 nerves leaving the midrib almost at right angles, mostly forking or 

 branching once or twice near the extremities, each division terminating 

 in one of the marginal serrations; base and apex not known. This leaf 

 by reason of the obtuse angle of divergence made by the secondaries with 

 the midrib, appears to be distinct from any species with which it was 

 compared. In some respects it resembles a Betula rather than an Ulmus, 

 but it apparently was inequilateral or cuneate at the base, as indicated 

 by the more rounded outline on the left side and the slightly curved mid- 

 rib. With an apex such as that shown in Fig. 11, Plate V, the leaf would 

 approach very closely to many forms of U. americana L. 



Occurrence. — Sunderland Formation. Point of Eocks, Calvert 

 County. 



Collections. — -Maryland Geological Survey. 



Ulmus pseudo-racemosa n. sp. 

 Plate LXXI, Figs. 11-13. 



Description. — Leaves varying in size, averaging about 2 inches in 

 length by 1 inch in width, oval to somewhat obovate in outline, inequi- 

 lateral, sharply and more or less doubly serrate; apex rather abruptly 

 acuminate; base cuneate or cuneate-cordate ; petiole short; nervation 

 simply pinnate, craspedodrome, the secondaries numerous, flexuous, vary- 

 ing in their angles of divergence from the midrib and mostly once to 



eral times forked, especially towards their extremities, the branches 

 of the forks terminating in the minor dentitions of the margin. 



It is almost impossible to separate these leaves from those of the living 

 U. americana L., and U. racemosa Thomas, and it is quite possible that 

 they are identical witli one or the other of these species. They may be 

 more or less satisfactorily compared with several fossil forms, such as 



