—— a 
[MATTHEW ] A BACKWARD STEP IN PALÆOBOTANY 119 
remarks occur repeatedly in his work on “The Fossil Plants of the 
Devonian and Upper Silurian Formations of Canada.” 
Notwithstanding the resemblances, Sir Wm. Dawson placed these 
plants in the Devonian System. At first when only a limited number 
of species were known, he thought them Upper Devonian,! but subse- 
quently on a better knowledge of the flora he transferred them to Middle 
Devonian. 
The present writer also in an article on the organic remains of the 
Little River Group, in which was a review and discussion of the Pre- 
Carboniferous Land Flora of North-Eastern America placed the column 
marking the St. John plant beds next the Carboniferous column on 
account of the strong resemblance between the two floras.® He did not, 
however, for a moment suppose that this resemblance in genera and 
species implied equivalence of age. 
One may suggest two hypotheses in explanation of the similarity 
of these floras, so widely separated in time. One is, that the “ Carboni- 
ferous plants” best known to us are to a great extent the species which 
flourished in marshy lands. Only in such places would deposits of coal 
of that time be formed, and these are the deposits which have been most 
extensively exploited. As we have already shown, the Little River plant 
beds were accumulated under similar conditions, and so present us with 
species of plants, insects and crustaceans parallel to their later con- 
geners of Carboniferous time. 
In England, deposits of this kind are not found below the Mill- 
stone Grit (though they are in Scotland), the Lower Carboniferous 
being a marine terrane, and the Devonian, red sandstones of a shallow 
sea, or the gray marine deposits of the southern coast. 
In Pennsylvania, again, the Carboniferous Flora (but here with a 
stronger Devonian facies) is well shown in the Pottsville Conglomerate 
Series. Mr. White finds this flora similar to that of the plant beds 
and claims that it is cotemporaneous. This is done on the basis of 
about a dozen species, out of the sixty or more of the Little R. Group, 
which he claims to be identical with species of this group. This Potts- 
ville fauna is shown to have about one hundred and fifty species and 
varieties; so that there are a great many more species different from 
those of the Little River Group, than are identical. 
There seems less reason to maintain Mr. Kidston’s view that the 
Little River plant beds are of the age of the Coal Measures. If one 
should take Lesquereaux’s Coal Flora of Pennsylvania and turn to the 
tabulated list of species at page 883 of Vol. III., he will find that about 
1 These Transact., vol. XII., sec. IV., p. 103. 
2 Jour. Geol. Soc. London, Nov., 1862, p. 327. 
