494 BROOKLYN BOTANIC GARDEN MEMOIRS 
Miocene oaks, of California, has been held to be varietally related 
to the existing golden oak of California, and is known as Quercus 
chrysolepis montana; but little can be said for or against this reputed 
relationship. Except for this, none of the Miocene oaks is thought 
to have survived. 
Little is known of the Pliocene in North America, and it may be 
that the sparing deposits in Maryland and Alabama that are supposed 
to be of this horizon may be open to some question whether they are 
not of more recent age. The 4 nominal species of Quercus that have 
been found in them are distinctly more like modern oaks than any- 
thing that preceded, but identities with existing species are not 
clearly evident to me (7). In South America, several fossil oaks from 
the Pliocene have been described, not evidently related to existing oaks, 
from localities far from any existing species (8). At present only 
four oaks occur in South America; these, which grow in the interior 
mountains of Colombia, form a natural group which appears more 
closely related to some of the Costa Rican oaks than to any others that 
are now known (9). 
If the term Pleistocene be used to designate glacial or later deposits 
in which fossils are found, it is to be assumed that these fossils will 
be very similar to if not identical with existing species. Scattered 
deposits of this kind have been examined from various points in the 
Atlantic region—Canada, New Jersey, Pennsylvania, Maryland, 
Virginia and Kentucky; and from California in the Pacific region. 
From these deposits 20 oaks have been named. Two of them, Q. 
predigitata Berry and Q. pseudo-alba Hollick, are separately designated 
as the ancestral forms respectively of Q. digitata or falcata and Q. alba, 
both of which are held to be represented by other Pleistocene material. 
A third, Q. abnormalis Berry, may have been a teratological bifid form 
of Q. Phellos, which is known in its normal form from Pleistocene 
deposits. Concerning a fourth species, Q. Glennii Hollick, I must 
admit a serious doubt as to the horizon to which it is ascribed. The 
remaining I6 species, into which I have merged Q. abnormalis, Q. 
predigitata and Q. pseudo-alba, are easily identified with species now 
living in the regions in which they have been found fossilized and, as 
would be supposed from this, all of these Pleistocene oaks are from 
the Atlantic region, except Q. chrysolepis, which was collected in 
California. 
Even a cursory inspection of the many illustrations of fossil oaks 
that have been published shows that collectively or for any given 
period they present a multiplicity of leaf forms more or less com- 
parable with what is known for existing species; indeed Professor 
Cockerell, who has given much attention to the point, finds in Quercus 
. 
