508 
PALAEONTOLOGY OF ILLINOIS. 
The number of European species recognized in the Coal'Measures of Illinois 
do not change in any way the relation of the American Coal Measures with 
those of Europe. It remains now the same as I have presented it formerly 
(Penn. Geol. Rep., loc. cit.). If general affinity is ascertained by a large num¬ 
ber of plants, either identical or closely related, geographical differences in the 
vegetation are indicated by peculiar species or races of ours, which as yet have 
not been observed in the Coal Measures of Europe. It is true that European 
paleontologists, though at work on the coal flora for more than a century, still 
discover species, either identical with or allied to some of ours, which were 
once considered as exclusively pertaining to the American coal flora; for ex¬ 
ample, a fimbriate Cyclopteris* from a small anthracite basin of the Swiss Al¬ 
pine mountains. But these cases are very rare indeed, and besides what is 
known from other parts of our coal fields, Illinois has now furnished a number 
of these peculiar types of vegetables, which render geographical disparity more 
appreciable. Of this kind are especially Neuropteris verbentefolia, JV. Evenii, 
N.pachy derma, Dictyopteris rubella, Alethopteris Tiymenophylloides , A. injlata, 
A. solida, Pecopteris Strougii, species of Stapliylopteris, /Sphenopteris scaberri- 
ma , Hymenophyllites mollis, Schutzia Iracteetta, a number of species of Lepido- 
dendra and Sigillaria, Syringodendron Porteri, Megapliytum McLayvi , species 
of Gaulopteris and of fruits of Palseoxyris. Indeed, no genus of our coal flora, 
except, perhaps, Calamites, can be considered as represented on both continents 
by species all identical or closely allied. As these points of difference, like 
those of affinity, have been observed from the beginning of the researches on 
the coal flora, and have not varied much in comparative quantity, they appear 
to fully corroborate the statement that, at the Carboniferous epoch, the flora 
which formed the constituents of the coal, was in Europe and in the United 
States as different, and at the same time as relatively alike, as is now the flora 
of the peat bogs of the two continents. 
* Cyclopteris lacerala, Heer., see descriptive part. The predominant species of this Alpine 
basin, which was for a long time considered as of a different formation from that of the Car¬ 
boniferous epoch, is Odontopteris Alpina, Brgt., a peculiar plant, which, as yet, with us,has 
been found only in connection with the anthracite of Rhode Island. 
