STAGE OP PLANTS IN OTHER BITUMINOUS BASINS. 293 



the Darlington and Middle Kittanning coals of Ohio and Pennsylvania 

 Over one-half of the species enumerated have heen collected from the 

 horizon first named, and nearly one-half from beds between the latter 

 coals. Almost one-half of the species are present in the D or E (" Marcy " 

 or " Pittston ") coals of the Northern Anthracite field, while nearly one- 

 fifth are found at higher horizons. With the plants of either the Morris- 

 Mazon Creek stage or the Cannelton horizon the affinities of our flora 

 would seem to be almost equally close; but while, as has already been 

 mentioned, the Missouri flora is almost wholly distinct from that of the 

 Pottsville series, and while it is far from confined to the characteristic 

 vegetal associations of the Brookville coal or coals A and B of the 

 Northern Anthracite field, the large number of species, especially those 

 of wide range, in the Middle Kittanning or higher coals, on the other 

 hand, is highly suggestive of a later age for the Henry County beds than 

 the Clarion or the Morris coals. Unfortunately the plants of the Free- 

 port coal group, as well as those of the entire Lower Barren Measures 

 (xiv), are almost entirely unexploited and unknown. There is little 

 room for doubt, however, that some of these more restricted forms will 

 be found to extend as high at least as the Freeport coals, although the 

 observed disappearance of the earlier forms in passing upward does not 

 warrant the expectation of finding many of the enumerated species at so 

 high a stage. The tendency of the observed range of the species to lead 

 us to conclude that the Henry Count}?- flora is later than that of Mazon 

 creek is strongly reinforced by the presence of several Pecopterids,* 

 whose identical or most closely related forms are not yet satisfactorily 

 known in beds lower if so low as the Kittanning coals. In fact, the ab- 

 sence of such later forms in the now fairly well known floras of the lower 

 coals of the Lower Productive Coal Measures (xiii), as well as the close 

 numerical and biological relations of our plants with those of the Kit- 

 tanning or higher coals, appear to justify the conclusion that the Mis- 

 souri plants are later than the Brookville and Clarion horizons, though 

 it is not likely that some of the earlier forms extend above the Kittan- 

 ning group, since they have not yet been met in or above the Middle 

 Kittanning or the Darlington coals. It seems probable, therefore, in view 

 of our present knowledge of the range of the Carboniferous species in this 

 country, that the stage of the lower coals of Henry county is not far from 

 the Lower Kittanning — a conclusion somewhat more definite than, though 

 not really disagreeing with, that reached by Professor Lesquereux.f 



IN THE ANTHRACITE SERIES. 



In the Northern Anthracite field, in Pennsylvania, the paleobotanical 



* For example, Pecopleris candolleana, Brongn. ; P. hemitelioides, Brongn. (?) ; Pecopteris cf. 

 arborescens, (Schloth.) Brongn., and a new species not yet known from any other region. 

 t Coal Flora, vol. iii, 1884, p. 879. 



