ably grew at a higher elevation than the typical ‘‘coal- 
swamp’ of near tide-level. This ecological difference 
may account for the scarcity of records in eastern North 
America. Nevertheless the extensive geographic distri- 
bution and relative abundance of Walchia, renders it one 
of the most useful Paleozoic plants in determining cor- 
relations and chronologies. 
Two recent discoveries of Walchia in western Amer- 
ican deposits indicate that the early appearance of such 
conifers is quite general. In Kansas Walchia, in a so- 
called Permian flora, is abundant in Conemaugh equiva- 
lents. There is no evidence of the presence of Callipteris, 
although Jongmans believed it to be common. The basis 
for his opinion was Dichophyllum moore: Elias. ‘The Penn- 
sylvanian age of these plants in Kansas is thoroughly 
demonstrated. The second occurrence of Wadlchia in sup- 
posed pre-Premian rocks is a single specimen from the 
vicinity of Fairplay, Colorado collected by Henry Don- 
ner. There are several determinable fragments in asso- 
ciation, but probably not sufficient for purposes of cor- 
relation. A small fragment, which I believe is referable 
to Callipteris naumanni would seem to suggest a Permian 
age, but the general consensus of opinion based on in- 
vertebrate faunas in the region is that the rocks are Penn- 
sylvanian. 
Precise determinations must be based on adequate 
material and precise correlations are possible only by 
means of a reasonably large number of specimens. Wal- 
chia in itself cannot give us the relative age of a late Pal- 
eozoic florule. Walchia in company with Taeniopteris 
indicates a zone in the immediate boundary between 
Permian and Pennsylvanian. With this common and 
widespread association—at least Stephanian in age—it is 
possible to determine the early appearances of Lescurop- 
teris, Callipteris, and Sphenozamites. 
[19] 
