n6 The American Geologist. August, 1903. 
in the remains of vertebrates^ and we may expect to hear much 
fr< mi him hereafter. 
.Mr. Lambe najturally accepts the determinations made by 
tlie members of 'he Geological Survey of Cannula regarding the 
age of the Belly River beds. Dr. G. M. Dawson. .Mr. R. G. 
MlcConnell, and Mr. J. !'». Tyrell have agreed that these heds 
lie below the Montana group, which includes the Pierre and 
Fox Hills deposit;-. The various strata which have been known 
to the geologists of the United States as the Laramie have 
almost universally been regarded as overlying- the Montana. 
Since one-half of the species of vertebrates described by Mr. 
Lambe are regarded by him as identical with Laramie species 
and most of the remainder are somewhat closely related, a con- 
flict of opinion has arisen. Two questions are propounded : 
I 1 ) Is there not an error in the determination of the position 
and age of the Belly River beds? ( 2 ) Do not some of the de- 
posits of the so-called Laramie of the United States occupy a 
lower horizon than has hitherto been supposed, a horizon 
ecpiivalent to that of the Belly River beds? 
Professor Osborn, in his first paper discusses the geolog- 
ical relations of the fauna as represented in Mr. Lambe's paper, 
the faunal characters, and the general relations of the fauna. 
His conclusions, as summed up on page 21, are to the effect 
that the Belly River fauna is more ancient in character than 
that found in the Laramie, that the interval represented by the 
Pierre-Fox Hills marine beds was accompanied by the ex- 
tinction of certain Jurassic types and progressive evolution of 
the persistent types, and finally that probably some of the fossil 
vertebrates described from Montana are of Belly River age. 
Hatcher in his latest communication holds that it is prema- 
ture to assert that the true Judith River beds, from which so 
many of the supposed Laramie species of vertebrates have 
been described, certainly overlie the Montana formation. 
Williston expresses himself as skeptical regarding the po- 
sition of the Laramie beds of Converse county. Wyoming, 
above the Fox Hills beds. 
Stanton declares himself emphaticallv of the opinion that 
the Judith River beds overlie the Pierre beds and are of more 
recent age. 
