WILLISTON. | The Kansas Niobrara Cretaceous. 243 
and of another a little less large, shows many variations in the 
arrangements of the plates. Among them are specimens which 
can not be distinguished from U. westfalicus, which I believe to be 
identical with socialis. 
It is not at all improbable that various species of crustacea will 
be found in the chalk. So far, however, I know of but a single one, a 
species of Cirrhiped figured in the accompanying Plate XX XVI, and 
which I will call Pollicipes Haworthi, after Professor Haworth, who 
discovered it near Gove City. Iam not quite sure that it belongs in 
the genus Pollicipes, but I believe the photographic illustration will 
render its recognition tolerably certain. The specimen is attached 
to a shell of an Ostrea congesta. Lying close by it are 'two more 
specimens, one of them about one-third the linear dimensions of the 
one figured, the other about one half. Its horizon is the yellow 
chalk. 
Fossil wood is occasionally found in the formation. A tree about 
thirty feet long was discovered near Hlkader a year or two ago. In 
the bark of fossilized wood fragments of. amber have several times 
been obtained. Near Russell Springs, Mr. H. L. Martin found a mass 
of pure charcoal imbedded in the chalk. I have never seen impres- 
sions of leaves. At several places in the upper part of the formation 
there occur thin seams filled with fragments of bones, scales, teeth 
and similar remains much broken up and comminuted. No coal, of 
any character has ever been discovered in the formation, and from 
the nature of the beds can not be expected. 
VERTEBRATES. 
The Niobrara deposits have been famous for the past twenty 
five years for the abundance, variety and perfection of its vertebrate 
remains. Many tons of fossils have been collected for various in- 
stitutions and individuals, among which may be mentioned Yale and 
Harvard Universities, the University of Munich, and of Kansas, the 
National Museum, Professor Cope, etc. In his publications, Professor 
Marsh has stated, or left it to be inferred, that his personal explora- 
tions in this as in other fields were extensive and that the larger 
part of the fossils described by him were the results of these ex- 
plorations. The actual fact is that since 1875, when my personal 
