410 H. D. Rogers's Observations on 
beds of anthracite in the coal-fields of eastern Pennsylvania, 
which, compared with the bituminous coal-measures of western 
Pennsylvania, appear not only to contain a greater variety of 
species, but to present them in a condition of more perfect 
preservation for study. 
The new species here briefly described by Mr. Lesquereux, 
constitute about one half of the total number of well-defined 
forms hitherto detected by him in the coal-measures and lower 
carboniferous rocks (the vespertine series) of Pennsylvania ; 
more than one hundred of the two hundred and twenty spe- 
cies examined by him proving to be entirely identical with 
species already recognized in the European coal-fields, and 
some fifty more of them showing differences so slight, that a 
fuller comparison with better specimens, may result in their 
identification likewise. As a further evidence of the near 
affinity of the North American to the European fossil flora of 
the carboniferous age, he has remarked, in the course of his 
investigations, that even these new species which seem re- 
stricted to this continent, are every one of them in close rela- 
tionship with European forms. It deserves mention, more- 
over, that the commonest European species are likewise the 
most common American ones. 
A stratigraphical analysis of the anthracite measures of 
Pennsylvania, calls for their division into two groups, à lower 
series, distinguished by the white or very pale color of the 
ashes of nearly all.the coal seams, and an upper series, 1n- 
cluding coals as remarkable for yielding only pinkish or red 
ashes. Between these groups there usually exists, especially 
in the southern or Pottsville basin, a small transition group of 
two or three beds of gray ash, or pinkish-gray ash coals. The 
entire number of coal-seams, of a thickness admitting mining; 
in the middle portion of the southern basin, where the whole 
formation is thickest and most replete in coal-beds, does not 
exceed about twenty-five; and counting those of all dimen- 
sions, the total series does not amount to more than from 
thirty to thirty-five separate layers. * 
