30 TRANSACTIONS OF THE 
this means to account for the seeming absence, to him, of the 
Lewis Shale. The main point which I think may have led 
to this condition is that the whole series which underlies the 
Laramie has been correlated with the Mancos Shale. Now 
the Mancos Shale, I find, agrees very well with the Colo- 
rado formation; and the Lewis Shale with the Montana. 
These two formations form the marine Cretaceous which 
underlies the series in question. Mr. Richardson knew that 
the Mesa Verde, as described by Holmes and Cross, was 
overlaid by marine Cretaceous strata. Not finding this the 
case here, he was obliged to use the unconformity hypothesis 
to account for this seeming irregularity in the Book Cliff 
Region. Then he shows a close lithological agreement, 
which, I find, is only true in a most general way, in that 
the coal bearing series is a complex of alternating sand- 
stones and clastic rocks. Nowhere in the Mesa Verde do 
we find any such sandstone as that I have called the Castle- 
gate Sandstone. (It was in this sandstone that a tibia of a 
_ Claosaurus was found some years ago by Robert Forres- 
ter in the vicinity of Castlegate). Most of the sandstones 
closely resemble those referred to:-as the Lower Sandstones. 
The presence of the Lewis Shale has been conclusively 
proven, as a complete suite of fossils ranging from the 
bottom of the Colorado to the top of the Montana. The 
latter formation contains many characteristic Fox Hills 
Species. This taken together with the unconformity at 
the base of the series in question and the entire absence of 
any marine forms in the Laramie or overlying strata, I 
believe justifies me in calling attention to this paper; and 
in refusing to accept the new classification until it is based 
upon more complete paleontological and stratigraphical 
investigations. To base a conclusion of so much moment 
on thirteen specimens that are at home more in the Laramie 
than in the Mesa Verde seems to me rather hasty. Where 
what Richardson calls a close stratigraphical agreement, it 
seems to me that he would have tried to obtain more 
palaeontological data. He does not show a single specimen 
of Viviparus in his list, and I know that in Horse Canyon, 
