Geological position of the Catskill group. — Prosser. 363 
paleontologist it is of especial value in this discussion and deserves 
the most careful consideration. 
McGill College, Montreal, February 18th, 1891. 
Dear Mr. Prosser: — In reply to your question respecting the age of 
the Catskill Flora — species of Archseopteris, Cycloptcris valida, Rhaco- 
phyllum t/runcatum (which I think is probably founded on a torn and 
imperfect specimen of my PlatypJvyllum broivnii, as Lesquereux 
himself suggested), Lycopodites richardsoni, Psilophyton princeps, etc., 
etc. I would say that such a flora, if found in Canada, would certainly 
be Upper Erian, and not Lower Carboniferous, for the following among 
other reasons : — 1st. This flora occurs at Scaumenac, Bay de Chaleur, 
in beds holding Pterichthys and other Devonian fishes, described by Mr. 
Whiteaves of our survey,* and underlying uncomformably the lower 
conglomerates of the Carboniferous (Bonaventure formation of Logan). 
These beds are mostly grey sandstones and shales with some red beds at 
top, and the Carboniferous conglomerates are also red, the whole ex- 
posed in fine sections. f 2d. We have in Nova Scotia, well exposed and 
rich in plants, the lowest Carboniferous which I have called the Horton 
Scries, and parts of which some of our younger geologists seem disposed, 
wrongly I think, to class with the Devonian. It contains a quite distinct 
flora (Lcpidodendron corrugatum, Aneimites acadica, etc.), not found 
anywhere in the true Upper Devonian beds. 
These reasons I regard as conclusive, and they cause me to consider 
the beds of Perry, in Maine, true Upper Erian, though it is apparently 
not easy to separate them stratigraphically from beds of similar mineral 
character in New Brunswick, regarded as Carboniferous. 
As the Erian flora migrated from the north and east, it is possible 
that south and west its plant types may be found at higher horizons, as 
has been supposed in Ohio (Newberry, Andrews,) and Virginia (Meek, 
Fontaine,) and therefore I would not be too confident as to these, but 
would be influenced by associations of other fossils and by distinct 
species of Devonian genera. As to the Catskill region, however, there 
is I think every reason to believe that it conforms nearly to our Cana- 
dian types of the formation. Truly yours, 
J. Wm. Dawson. 
It must not be hastily concluded that if the dividing line be- 
tween the C arbonif erous and Devonian be lowered from the top of 
the Catskill to its base that it will always give a precise dividing 
line. On the contrary it is doubtful if in the Appalachian Pale- 
ozoic area the line separating the Catskill from the Chemung can 
be determined with as great precision as the line between the 
Catskill and Pocono. Professor Williams has previously called 
attention to the difficulty of separating the Chemung from the 
*Proc. and Trans. Royal Soc. Canada, Vol. IV, Sec. IV, p. 101. 
fSee Fos. Plants Erian and Up. Sil., Pt. II, pp. 98-102. 
