Bulletin 3. The flora of the Raritan Formation, 1911 - State of New ...

JUGLANDALES.
Io9
Descriptio_.--Leaves variable in size, i.I. cm. to 5 cm,.in length
by o. 4 cm. to 2 cm. in breadth, ovate !anceolate in outline with an
obtusely pointed apex and a cuneate, slightly decurrent base.
Margin divided into from g to 4 sligbtly aquiline, rounded,
obtusely pointed lobes, the intervening rounded sinuses cut about
half way to the midrib. Secondaries craspedodrome, one to
each lobe. In the larger leaf there .is a second secondary some
distance below the one which traverses one of the lobes, and,
while this is not visible throughout its length, it was probably
camptodrome as in the leaves 04 the modern Comptonia.
It is difficult to understand on what ground Prof. IKeer
founded hls two species pafvuhz and parvifolic_ unless it was
because they were supposed to have come from different geological
horizons. He compares both to the European Coanptonia
ce_i*tgensis A1. Br., although their resemblance to that
species, as a naatter of fact, is not very close. The two are exactly
similar, as is the Rheas included in the foregoing synonymy,
except as to size. The Raritan specimen which Newberry identi- --//
fled as parvula is closer to parv_folia, which fact is noted by the
latter author, who presumably hesitated to refer a Cretaceous
leaf to a species of the Miocene, as these Arctic deposits were
thought to be at that time. The writer has elsewhere (loe. cit.)
called attention to the probability of Heer's specimens having
come from practically the same horizons, so that there are no
valid reasons for maintaining their fancied distiuctness.
The earliest leaves of the modern Comptonia peregri_a
(Linn6) Coulter usually are very similar to this fossil species.
These latter might be considered as the abbreviated leaves, so
common in seedling plants and hence without phylogenetic meaning,
or they may be considered as representing the normal leaves
of these ancient Comptonia plants. The first assumption seems
doubtful, not only because of the perishable nature of seedling
leaves in general, but because it is unusual for them to become
detached and fossilized, and it would be a rather singular coincidence
for this to have occurred in New Jersey, Greenland, and
Europe only once and at the same geological horizon. Furthermore,
no other species of Comptonia are known from either the
Raritan clays, or the Atane and Patoot schists, from which they
8 PAt,
NEW JERSEY GEOLOGICAL SURVEY