No. 471] CRETACEOUS PLANT REMAINS 191 
name was made to include several different fragments which were 
subsequently ascertained to belong to two or more distinct species. 
The identification or determination of a genus solely from the 
shape or superficial markings of a cone or some of its detached 
scales or of a leaf or a leafy twig, can seldom be entirely conclusive 
or satisfactory; but it may be readily appreciated that if, in addi- 
tion, the internal structure of such specimens can be made out by 
the use of the microscope, not only may the genera be thus deter- 
mined beyond question, but many fragmentary scattered remains, 
presenting no superficial characters of any diagnostic value, might 
thus be identified and brought together into their true generic and 
specific relationships. 
Superficial examination of the Kreischerville material showed 
that it contained a number of recognized species, descriptions of 
which were based upon well defined external characters, besides 
quantities of specimens which were not identifiable by ordinary 
means. ‘This indicated a specially favorable field for investiga- 
tion, of which advantage was taken, and the methods employed, 
together with some of the selected results obtained, are here de- 
scribed 
DESCRIPTION OF THE Gross MATERIAL 
Botanical Characters of the Plant Remains.— A rough exam- 
ination of the gross material showed the presence of pteridophytes, 
angiosperms, and gymnosperms. The remains of the pterido- 
phytes were exceedingly fragmentary and unsatisfactory. Those 
of the angiosperms consisted for the most part of dicotyledonous 
leaf impressions in the clay, usually accompanied by a thin film 
of carbonaceous matter, which generally disappeared on exposure 
to the air. 
The remains of the gymnosperms proved to be more satisfactory, 
however, being represented not only by isolated coniferous leaves 
which retained more or less of the substance of the plant, but also 
by leafy twigs and branches, cones and cone scales, and fragments 
and logs of lignite, some of which contained amber in their inter- 
stices. Special attention was therefore given to these remains 
amongst which specimens of the following genera and species 
were separated out and identified. 
