vestigators have concurred in this opinion. 
The specimen from Prince Edward Island, which 
was sent in a small lot by Bain in 1875 includes: Cadlip- 
teridium aff. pteridium, Pecopteris arborescens, Alethop- 
teris grandini, and Sphenophyllum oblongifolium.” Small 
fragments of Walchia are abundant. The matrix of the 
rock is a red micaceous sandstone of fine grain. This as- 
semblage presents no Permian indicators but rather re- 
sembles the typical Monongahela ( =Stephanian) flora of 
Pennsylvania. 
Walchia is known to occur in the Upper Carboni- 
ferous of England,” Wales,” France,” and elsewhere,” 
although it is characteristic of the Lower Permian. No 
reliance is placed upon its presence as an indication of 
Permian age. However, it is a precursor of the typical 
Permian flora to come. In this sense its appearance is an 
important factor in determining the process of plant se- 
quence in the late Paleozoic. 
Walchia had been sought in Pennsylvania for fifty 
years without reward, but its rarity is of less importance 
than its presence. David White” believed that some 
physiographic or climatic barrier prevented the migra- 
tion of conifers into the area of Dunkard deposition. 
It is true that during the Conemaugh, orogenic 
movements associated with the Appalachian revolution 
caused many lasting changes in regions to the west in 
Pennsylvania. It is also true that the rapid plant evolu- 
tion and floral changes in western Pennsylvania, were 
contemporaneous with these earth changes. 
Darrah, loc. cit. p. 4 
“Crookall, Coal Meas. plants. 1929 
“Dix, Trans. Roy. Soc. Edinb, vol. 57. p. 815. 1934 
“Bertrand, C. R. Congr. Strat. Carb. p. 109. 1928 
“Gothan, Carb. u. Perm. Pflanzen 
17 F : - 
Personal Communication dated June 26, 1938 
[16 ] 
