166 KANSAS ACADEMY OF SCIENCE. 
limits of the Kiowa shale, representing, probably, the extreme limits of the Bel- 
viderean sea at the beginning of the Dakota epoch. 
The first collection of fossils from this locality contained twelve species. 
From time to time additions have been made to this number, until probably fifty 
species have been recognized from these beds. The fossils have all been found 
in the lower part of the Cretaceous of the region, probably all within 100 feet of 
the Permian. Above these horizons no more shells are found in the Dakota 
until the upper layers are reached. Meek and Hayden mention three inverte- 
brates found near the mouth of the Big Sioux river, and a few additional species 
have since been found in the same locality. Professor Hicks discovered a lo- 
cality in Jefferson, county Nebraska, from which Doctor White identified seven 
species. During the summer of 1889 the writer discovered two localities in the 
upper part of the Dakota from which shells were obtained. One of these is near 
Glasco, Kan., and the other at Jackson, Neb. The horizon of these widely 
separated localities is practically the same, being about fifty feet below the base 
of the Benton. The shells were submitted to Dr. T. W. Stanton, our best au- 
thority on Cretaceous invertebrates, and were referred by him to a number of 
species hitherto found in either the Big Sioux or the Jefferson county localities. 
Doctor Stanton states that the shells from the Mentor have not been found in 
the upper layers of the Dakota, and vice versa, with the possible exception of 
some species of Ostrea of which the identification is uncertain. 
Mr. Logan, however, reports species from the upper beds which are also 
found in the Mentor. The following quotation is from Mr. Logan’s paper: ‘In 
the upper Dakota group fossils have been found in three horizons. In the thin 
sandstone layers of the first shale bed the following fossils were found.’’ {Then 
follow the names of fourteen shells.}] ‘‘In the saliferous-shale horizon was 
found a bed of fossils, of which the following have been determined. 
Altogether, more than twenty-five species have been found in the Dakota.’’® 
Of the shells mentioned by Mr. Logan, at Jeast eight have been recorded as 
occurring in the Mentor, either in Saline county or near Marquette, while several 
are among those which have been found only in the upper part of the group. 
The writer makes no pretensions to a knowledge of invertebrate paleontology, 
and consequently disclaims the ability to intelligently discuss the question. 
VERTEBRATES, 
The paucity of vertebrate fossils in the Dakota has long been a matter of note. — 
As late as 1898 Doctor Williston said: ‘‘ No vertebrate remains of any kind have 
so far been discovered in Kansas or elsewhere, save some impressions or casts. 
A record of footprints from this formation was first made by Prof. B. F. Mudge 
in 1866, and a later one by Prof. F. H. Snow.’’*? 
The tracks described by Professor Mudge were found by him in the valley of 
the Republican river, about fifty miles from its mouth. The slab containing the 
prints was lost at the Kansas agricultural college. It is but just to say that the 
vertebrate origin of the prints has been questioned, and Professor Mudge himself 
was led to believe that they were the work of Indians. 
The track described by Professor Snow was secured on Thompson creek, Ells- 
worth county, Kansas, in 1885, by Judge E. P. West. The horizon from which 
the specimen was taken is about the center of the group. The slab containing 
the track is now preserved in the museum of the Kansas university. The im- 
pression is evidently avian in character, and has been so regarded by vertebrate 
paleontologists. 
58. Univ. Geol. Surv. of Kansas, 2: 212. 59. Loc. cit., 4: 50. 
60. Trans. Kans. Acad. Sci., 10: 3. 
