Subdivisions.New York and
Western Canada.		Gaspé and
Bay des Chaleurs.		Southern
New
Brunswick.		Coast
of
Maine.
Upper
Devonian or
Erian.		Chemung
Group.		Upper
Sandstones.
Long Cove, &c.
Scauminac
Beds.		Mispec Group.
Shale,
Sandstone,
and
Conglomerate.		Perry
Sandstones.
Middle
Devonian or
Erian.		Hamilton
Group.		Middle
Sandstones.
Bois Brulé,
Cape Oiseau,
&c.		Little R. Group
(including
Cordaite
Shales and
Dadoxylon
Sandstone).
Lower
Devonian or
Erian.		Corniferous
and
Oriskany groups.		Lower
Sandstones.
Gaspé Basin,
Little Gaspé,
&c.
Campbellton
Beds.		Lower
Conglomerates,
&c.

It may be proper, before closing this note, to state the reasons which have induced me to suggest in the following pages the use of the term “Erian,” as equivalent to “Devonian,” for the great system of formations intervening between the Upper Silurian and the Lower Carboniferous in America. I have been induced to adopt this course by the following considerations: 1. The great area of undisturbed and unaltered rocks of this age, including a thickness in some places of eighteen thousand feet, and extending from east to west through the Northern States of the Union and western Canada for nearly seven hundred miles, while it spreads from north to south from the northern part of Michigan far into the Middle States, is undoubtedly the most important Devonian area now known to geologists. 2. This area has been taken by all American geologists as their typical Devonian region. It is rich in fossils, and these have been thoroughly studied and admirably illustrated by the New York and Canadian Surveys. 3. The rocks of this area surround the basin of Lake Erie, and were named, in the original reports of the New York Survey, the “Erie Division” 4. Great difficulties have been experienced in the classification of the European Devonian, and the uncertainties thus arising have tended to throw doubt on the results obtained in America in circumstances in which such difficulties do not occur.

These reasons are, I think, sufficient to warrant me in holding the great Erie Division of the New York geologists as the typical representative of the rocks deposited between the close of the Upper Silurian and the beginning of the Carboniferous period, and to use the term Erian as the designation of this great series of deposits as developed in America, in so far at least as their flora is concerned. In doing so, I do not wish to introduce a new name merely for the sake of novelty; but I hope to keep before the minds of geologists the caution that they should not measure the Erian formations of America, or the fossils which they contain, by the comparatively depauperated representatives of this portion of the geological scale in the Devonian of western Europe.

VII.—On the Relations of the so-called “Ursa Stage” of Bear Island
with the Palæozoic Flora of North America.

The following note is a verbatim copy of that published by me in 1873, and the accuracy of which has now been vindicated by the recent observations of Nathorst:

The plants catalogued by Dr. Heer, and characterising what he calls the “Ursa Stage,” are in part representatives of those of the American flora which I have described as the “Lower Carboniferous Coal-Measures” (Subcarboniferous of Dana), and whose characteristic species, as developed in Nova Scotia, I noticed in the “Journal of the Geological Society” in 1858 (vol. xv.). Dr. Heer’s list, however, includes some Upper Devonian forms; and I would suggest that either the plants of two distinct beds, one Lower Carboniferous and the other Upper Devonian, have been near to or in contact with each other and have been intermixed, or else that in this high northern latitude, in which (for reasons stated in my “Report on the Devonian Flora”[BZ]) I believe the Devonian plants to have originated, there was an actual intermixture of the two floras. In America, at the base of the Carboniferous of Ohio, a transition of this kind seems to occur; but elsewhere in northeastern America the Lower Carboniferous plants are usually unmixed with the Devonian.

[BZ] “Geological Survey of Canada,” 1871.

Dr. Heer, however, proceeds to identify these plants with those of the American Chemung, and even with those of the Middle Devonian of New Brunswick, as described by me—a conclusion from which I must altogether dissent, inasmuch as the latter belong to beds which were disturbed and partially metamorphosed before the deposition of the lowest Carboniferous or “Subcarboniferous” beds.

Dr. Heer’s error seems to have arisen from want of acquaintance with the rich flora of the Middle Devonian, which, while differing in species, has much resemblance in its general facies, and especially in its richness in ferns, to that of the coal-formation.

To geologists acquainted with the stratigraphy and the accompanying animal fossils, Dr. Heer’s conclusions will of course appear untenable; but they may regard them as invalidating the evidence of fossil plants; and for this reason it is, I think, desirable to give publicity to the above statements.