374 The American Geologist. J""*^' i^''^. 
Dr. Williston find any such thickness given for the Fox Hills 
as that which he mentions here? Even the thickness of 3000 
to 4000 feet at one time ascribed to it by King is now known 
to be much too great, the real thickness scarcely, 'if at all, ex- 
ceeding 500 feet. Perhaps if he reduces the thickness of these 
beds to their usually ascribed limits the persistence of certain 
types of animals will not then seem so "incredible" as he had 
at first supposed; although I do not for a moment wish to be 
understood as accepting the evidence brought forward by Dr. 
Williston from the fossils as of anything like the importance 
which he attaches to it. 
Such paleontological evidence as he does present in support 
of his position is, to my mind, largely invalidated by two very 
grave objections. First of these is the fact that, as stated by 
Williston, in almost every instance the genera and species 
enumerated are represented, by only fragmentary and isolated 
material, and hence their generic or specific identity cannot be 
determined with certainty. Second, several of the forms men- 
tioned like Baena, Lepidotus^ Acipenser, etc., pertain to per- 
sistent types which, even if their specific identity were not 
questionable, would still be of very little value for purposes of 
correlation. 
Dr. Williston's inference that professor Marsh neglected 
to mention certain forms from Wyoming because he consid- 
ered them identical with others already known from Montana 
is, I think, more logically explained by the very fragmentary 
nature of the remains and Marsh's well known aversion to 
dealing with fragmentary or relatively unimportant material 
and seeking after the "choicest plums," as he used frequently 
to express it. It is noticeable that in almost every instance in 
which he did treat of related forms from the Wyoming and 
Judith River Beds he considered them as both generically and 
specifically distinct ; note, for example, the different forms of 
the Ceratopsidse and Trachontidje (Claosauridre) described 
by him. 
While there is, at present, some doubt as to the exact strat- 
igraphic position, of the Judith River beds of INIontana, it 
would seem that no such statement can be made as to the Belly 
River beds of Canada or the Laramie (Lance Creek) beds of 
Converse county, ^Wyoming. The stratigraphical position of 
