100 : Arthur Hollick. 
XXXII. Species novae Pleistocaeniae Marylandicae 
ab Arthur Hollick descriptae. 
(Ex: Contr. New York Bot. Gard., no. 85, in: Maryland Geolog. Surv., 1906, 
p. 217—231, pl. 67—75.) 
1. Hicoria pseudo-glabra Hollick, |. c., p. 221, pl. LXXII, fig. 1, 16, 17 
[fossil]. 
Terminal leaflet broadly obovate in outline, wedge-shaped at the 
base, finely serrate except near the base, short petioled; midrib thick; 
secondaries numerous, irregularly disposed, diverging from the midrib at 
obtuse but varying angles, mostly forking or branching once or twice 
near their extremities, the branches extending to the serrations; tertiary 
nervation fine and close. Lateral leaflets lanceolate (?) in outline, rounded 
and inequilateral at the base, entire below, serrate (?) above; secondaries 
irregularly disposed, sub-parallel, curving upward near the margin, the 
upper ones branching near their extremities. 
These specimens are so contorted or imperfect that accurate description 
or comparison is impossible. They have much the appearance of many 
leaflets of the living H. glabra (Mill) Britton, in which the serrations are 
often obscure or entirely wanting below. The terminal leaflet may also 
be compared to Aesculus simulata Knowlton (Bull. U. S. Geol. Survey, 
no. 204, p. 78, pl. XV, figs. 1, 2) which is apparently a Hicoria rather 
than an Aesculus. The thick midrib, short petiole, entire, wedge-shaped 
base, and the irregular angle of divergence of the secondaries together 
with their branching extremities, are characteristics which are common | 
to the Maryland specimen and to those figured by Knowlton. It is pos- 
sible that Fig. 4, Plate LXX, may belong to the same species. 
Sunderland Formation. Near the headwaters of Island Creek, 
Calvert County. Maryland Geological Survey. 
2. Populus Clarkiana Hollick, l. c., p. 228, pl. LXX, fig. 6 [fossil]. 
Leaf deltoid in shape, slightly rounded at the center, rather abruptly 
acuminate above, cuneate or sub-cordate below, crenulate-dentate except 
near the base and apex; petiole about ?/,9 inch long; nervation 3-palmate; 
lateral primaries and principal secondaries spreading, sub-parallel, campto- 
drome; from the under sides of the lateral primaries and from the outer 
sides of the marginal loops of the secondaries a series of fine nerves and 
nervilles-extend to the crenulations of the margin. 
Named in honor of Professor W. B. Clark, under whose auspices the 
collection was made. There are no described or figured species with 
which this leaf may be satisfactorily compared, but it approaches very 
close to some of the forms of P. deltoides Marsh, especially var. occi- 
dentalis Rydb. 
