Geological position of the Catskill group. — Prosser. 353 
Bothriolcpis Jeidyi Newb. Holoptychius (?) radiatus Newb. 
Sauripteris taylori Hall. Ghjptopomus sayrci Newb. 
Holoptychius americanus Leidy. Dipterus( Ctenodus)sherwoodi Newb 
" giganteus (?) Ag. " " radiatus Newb. 
" /iffl//j Newb. Gyracanthus sherwoodi Newb. 
The crustaceans are represented by Stylonurus excelsior Hall 
from Andes, New York and Meshoppen, Penn'a. A species of 
lamellibranch, Amnigenia catshillensis (Van.) Hall, which is 
rather characteristic of the Oneonta sandstone, has been reported 
from the Catskill of Bedford Co., Penn'a. ,* and it is not at all 
improbable that it will yet be found at other localities in the typi- 
cal Catskill. 
So far as paleontology is concerned, the principal change in- 
volved in this correlation is in reference to the paleobotany. By 
including the Catskill in the Lower Carboniferous a considerable 
proportion of the American Devonian flora would be transferred 
to the Carboniferous or Pennian system. It will be remembered 
that Sir Wm. Dawson, to whom we are indebted for most of the 
description of this flora, has always insisted that it is a Devonian 
flora quite distinct from that of the Lower Carboniferous. This 
opinion was clearly stated by Dawson in 1882 when he defined the 
" Upper Erian Sub-flora " as corresponding "to the Catskill and 
Chemung of the New York series, and to the Upper Devonian of 
Europe," and stated, in conclusion, that it is "very distinct from 
that of the Lower Carboniferous, "f 
A rather careful review of the fossil plants, now known to oc- 
cur in the typical Catskill of the United States, fails to show any 
marked reason for considering them as necessarily Devonian. In 
fact some of the other paleobotanists have been inclined to con- 
sider the flora of the Upper Devonian as of Lower Carbonifer- 
ous facies. The mogt abundant ferns in the Catskill belong to 
the genus Archceopteris, which appeared in the Chemung and 
probably extends through the Lower Carboniferous into the Coal 
Measures. This genus is represented in the Culm of Austrian 
Silesia, Hesse, Moravia, and Silesia by several species, also in the 
*2d Geol. Surv. of Penn'a. T 2 . The Geology of Bedford and Fulton 
counties, p. 103. It is mentioned under the name of Modiola a/ngusta 
Con., which is considered a synonym of A. catskillensis (Van.) Eall. See 
Geol. Surv. N. Y., Pal. Vol. V., Pt. I, Lamellibranchiata II, pp. 516, 517. 
fGeol. Surv. of Canada. The fossil plants of the Erian (Devonian) 
and Upper Silurian formations of Canada. Pt. II. p. L30. 
26 
