66 KANSAS ACADEMY OF SCIENCE. 
undescribed species of the genera Unio, Linearia, Homanya, Cymella, Corbuia, 
Glauconia, Anchuria, Sphenodiscus, and Ostrea. The other five are Rondaria 
quadrans Crag., Tapes belviderensis Crag., Mesalia kansasensis Meek, Tur- 
ritella belviderei Crag., Pyrgulifera meekii White. 
Professor Stanton in writing says: ‘‘It isnoteworthy that your collection con- 
tains relatively few of the species described by Meek and White in Mudge’s collec- 
tion from the same region, while it does contain a large proportion of species that 
occur in the Comanche series of southern Kansas, Texas, and New Mexico,”’ and 
asks if I am certain that I have specimens from the same horizon as Mudge’s. 
I have stated to him in reply that a number of the fossils I sent are from within 
a mile of Mudge’s collecting ground, and unquestionably in the same horizon, 
according to the statement of Mr. Hall, livingsouth of Bavaria, who hasdirected 
me to what he says is the precise locality of Professor Mudge’s collecting. 
It will thus be seen that the recent additions to the fauna seem to indicate a 
close relationship to the Comanche, while the occurrence of Pyrgulifera meekii 
seems to suggest relationship with the Bear River formation of Wyoming, accord- 
ing to Professor Stanton. Asa result of my studies during the past year, Iam 
Still of the opinion that the Mentor proper is at the base of the Dakota, and 
entirely below the leaf-bearing strata, although I have found in a very few in- 
stances what appear to be wood-stem or root impressions associated with shells; 
and have frequently found fossil leaves within ten feet above them, but never 
associated with or below the she!] beds, and generally the Permian floor is close 
below the shell-bearing stone. 
Another peculiar feature is that every different outcrop, even when only short 
distances intervene, but especially when separated by intervals of a few miles, 
shows a decided difference in prevailing species of fossils, some localities yielding 
brackish or fresh-water species, while others are entirely marine, indicating that 
this region was near a shore line with brackish water bays or estuaries. 
‘The lithological character varies decidedly with different localities also, and 
this summer I obtained from a very limited outcrop, near Brookville, some of 
the finest fossils, I think, that have ever been obtained from the Mentor. The 
stone is an argillaceous sandstone, varying from a pinkish color, through yellow- 
ish and reddish tints, to brown, very hard and fine grained, and the fossils 
broken out of it are very perfect, every detail of marking being clear and distinct 
on some of the specimens. This locality also yielded some new forms having 
several casts of a new species of Anchuria and the first of the ammonite forms 
that I have found in the Mentor, a species of Sphenodiscus. 
In addition to this, Mr. Davis Boyles, who has been taking special work in 
geology at the Kansas Wesleyan, made the very interesting discovery of a fossil 
bed northwest of Brookville that yielded some excellent specimens of fossil leaves 
associated with abundant casts of a mollusk, Modiolo polii White, (this species 
was described from the Bear River beds,) and in the same lot of material were 
three distinct impressions of beetle wings, the first insect fossils that I have 
obtained from the Dakota. 
These fossils were from the upper Dakota, not more than 50 or 60 feet below 
the Fort Benton limestone that caps the hill tops a short distance from where 
the fossils were collected, and about 300 feet higher than the Mentor beds near 
Brook ville. 
The Dakota and its associations furnish a very interesting field of study for 
the geologist, and the rather limited shell beds at the base of the Dakota known 
as the ‘‘ Mentor beds”’ are among the interesting features. 
