123 
and is associated with “ kaolin” and white plastic clay, presumably 
of Cretaceous age; yellow gravel and sand, representing. probably 
a recent Tertiary horizon and water-worn fragments of serpentine 
rock. These materials form a sort of hummock, beneath and dis- 
tinct from the typical red bowlder till on top and afford every evi- 
dence of having been carried forward by the advancing glacier of 
the Ice Age, which, upon melting, deposited on top the debris 
which we call the bowlder till.* 
The conglomerate, with its included fragments of vegetation, 
is, therefore, certainly pre-glacial in age. The direction of gla- 
cial movement on Staten Island was from the northwest, and 
as a line from the locality in question towards this point of the 
compass would cross the serpentine and limonite area of the Is- 
land we would naturally infer that it was from there that the con- 
glomerate was derived. Throughout this area there are numerous 
deposits of limonite, associated with yellow gravel under favorable 
conditions, occupying basin-like depressions in the serpentine and 
evidently representing old swamps, around or in which a semi- 
aquatic vegetation flourished, prior to the advent of the Ice Age. 
Furthermore, as no such combination of yellow gravel, limonite 
and serpentine is known to occur elsewhere on the line of glacial 
movement, towards the locality where the conglomerate was 
found, we are justified in inferring that our specimens are native 
to Staten Island. 
The problem of the exact geologic age of the yellow gravel 
conglomerate and, therefore, of the vegetation contained in it, has 
not been completely solved. Upon stratigraphic grounds Pro- 
fessor R. D. Salisbury decided it to belong to his Beacon Hill for- 
mation, which he classes as Miocene Tertiary in age.+ It is, 
therefore, of interest to ascertain how the evidence afforded by 
fossil plants compares with this conclusion. 
Grasses, as fossils are comparatively rare, and are not definitely 
known prior tothe Tertiary period, although monocotyledons under 
the generic names of Poacites, Bambusium, Culmites, Arundo and 
*For the geological features of the locality see description in Proc. Nat. Sci. Anss, 
Staten Isld. 2: 8; 3: 8; 3: 45-47, and Trans. N. Y. Acad. Sci. IT: 1045 14: 15, 
S8- 4 
+ Ann. Rept. State Geol., N. J., 1894, 100; 1895, 3. 
