Geological position of the Catskill group. — Prosser. 361 
3. Archceopteris rogersi(Dn. )Lx. 12. Lycopodites comosus Dn. 
4. Carpolithus lunatus Dn. 13. " ricliardsoni Dn. 
5. " siliqua Dn. 14. Psilophyton elegans Dn. (?) 
6. " spicatus Dn. 15. " glabrum Dn. (?) 
7. Cordaites flexuosus Dn. 16. " princeps Dn. (?) 
8. Cyclopteris (Platyphyllum) 17. Sphenopteris recurva Dn. 
brownii Dn. 18. Stigmaria pusilla Dn. 
9. Lepidodendron gaspianumDn 19. Trichoma nites filicula Dn. * 
Ten of the above species are confined to Periy and the geologi- 
cal range of the remaining nine is given below. The range of 
ArchcBopteris jacksoni Dn. was given under the list of plants from 
the Catskill of Penn'a. and New York ; while A. rogersi (Dn.)Lx. 
is in the Catskill of Penn'a. and Pocono of Va. Lepidodendron 
gaspianum Dn. ranges from the Hamilton of N. Y. to theSubcon- 
glomerate of Ohio, and Leptophloeum rhombicum Dn. t occurs in 
the Lower Devonian of Campbellton, N. B., and Middle Devonian 
of Graspe, Lower Quebec. Lycopodites ricliardsoni Dn. occurs in 
the Catskill of Penn'a, and Cyclopteris {Platyphyllum) brownii Dn. 
may be the fructification of one of the above ferns of the genus Arch- 
seopteri*. I regard this as quite possible, but have no direct evidence 
of it" (Fos. Plants Dev. and Up. Sil., Pt. I, p. 49.) Under the de- 
scription of the species it is further stated that "The suggestion of 
Schimper that this species may be founded on fertile pinnules of 
Cyclopteris of the subgenus Archaaopteris, is deserving of attention" 
(Ibid., p. 52); while, on p. 191 in explanation of fig. 175 of pi. XV occurs 
the statement that " This species may probably be founded on fertile 
pinnae of Cyclopteris Jacksoni. " Lesquereux in 1880 wrote "That this 
figure represents the fructification of a species of Archceopteris is posi- 
tive, and Prof. Dawson has already recognized the accuracy of this 
reference; but,in the absence of sterile leaflets, it is not possible to say 
to what species the fragment is referable " (2d Geol. Surv. Penn'a. P, 
Coal Flora, p. 304.) This opinion was re-affirmed by Lesquereux in 1884 
when he said that "This plant as figured, appears to represent fruiting 
branches of some species of Archseopteris (Ibid., Vol. Ill, p. 837.) 
Finally, Dawson in 1889 provisionally accepts this synonomy and states 
that he " refers this fructification to A. jacksoni, because that is the 
only species found with it." (Ibid., P 4 „ Vol. I, Errata, p. VI.) 
*In addition to the above list Dr. Dawson has identified specimens as 
belonging to the following genera; but, owing to the imperfection of 
the material, he has not been able to identify them specifically. 
1. Aporoxylon sp. Dn. cf. primigenium Ung. 
2. Cijperitcs sp. Dn. 
3. JDadoxylon sp. Dn. cf. ouangondianum Dn. 
4. Megaphyton ? sp. Dn. 
5. Unnamed pinnule of fern. 
fWni. Carruthers in 1ST:.' (Quart. Jour. Geol. Soc. London. Vol. 
XXVIII, p. 351) stated that he regarded this species as a fragm'ent of 
Lepidodendron gaspianum, and on p. 353 identified itasL. nothumUng. 
non Salter. Dawson in 1882 (Fos - . Plants Erian and Up. Sil., Pt. II, 
p. 105) reaffirmed the distinctness of these two species and gave a 
synopsis of their more distinctive characters. 
