676 KANSAS CITY REVIEW OF SCIENCE. 
discovered in the bluffs near Ft. Harker a number of species of the avalia. A. 
quinguepartita has five lobes, margin entire, while 4. saporteanii has five large lobes 
with dentate margin—both are very fine species, and allied to our highest families. 
of existing trees. <Avala tripartita (or imperfecta) isa smaller species with thirteen 
entire lobes. A number of other species have been described by Lesquereux, 
showing that this magnificent tree was well represented by numerous species in 
the Cretaceous forest. ‘The sassafras, as I have said, was the first plant to excite 
interest. It is represented by a number of species—S. mradile is a large leaf 
with three lobes, having a wavy and dentate margin ; .S. cretaceum and others are 
very abundant in the sandstone of Ellsworth county, Kansas. A closely allied 
genera is c7sszfes—in fact, its species have usually gone under the genus sassafras. 
Cissttes Harkerianum and obtusum are very common. ‘The stately plane, poplar, 
oak, black walnut and many others left their leaves imbedded in the sandstone of 
the Dakota Group. One magnificent specimen I found near Ft. Harker belongs 
to the genus aspidiophylum and species trilobum. I have found specimens a foot 
in length and breadth. One peculiarity of the species is, that the midrib is per- 
follate—an ear projecting below the stem. Another species with perfoliate mid- 
rib is Protophyllum Sternbergii—a leaf one foot in length and six inches wide, with 
undulate margin. The graceful leaves of the menzspermites and poplar are often 
found. The texture of the rock is so fine-grained that the midribs, nerves and 
outline are as finely imprinted as if done in wax. I believe I can claim the 
honor of being the first to obtain pine cones from this formation. 
Dana says in an old manual that they are not found in the cretaceous. One 
beautiful cone with leaves is described in Lesquereux’s Review of the Cretaceous, 
under the name of Pinus guenstez. Among the semi tropical plants is the cin- 
namon and fig. The common plum is also found. We have, therefore, at the 
opening of the cretaceous a flora rich in recent genera. Not only do lowly forms 
appear, but the highest families of our forest trees; each species representing a 
perfect tree with no known ancestors. How can we reconcile this fact with the 
thecry of evolution, where long ages are required for the perfection of species, 
and where the geological record should show these transformations, step by step, 
from lowly forms to the perfect tree. Certainly the records show no such ad- 
vances in the vegetable kingdom. But as early as the Cretaceous we find as per- 
fect a flora as exists to-day, without even the Trias or Jura to draw from. The 
Dakota limestone lies on the shales and limestone of the Permian. The forma- 
tion has been but little explored, and the rich returns from limited areas led us to 
expect many new species when the rocks are explored. The sandstone is valua- 
ble for building purposes. The Post Hospital at Fort Harker is built of thiss tone, 
and though it his been dismantled, and the wood work carried away, the walls 
still stand, and the rains of summer, and frosts and storms of winter have been 
unable to crumble them in ruins. Beds of lignite are found in Ellsworth county 
that are of great value to the inhabitants. Potters’ clay is also found, as well as 
iron ore, aluminous shale, iron pyrites, and crystalized gypsum. ‘The iron ore 
