754 A. C. PEALE 
are known only from fragmentary remains and that future researches may 
show specific differences in some of them, but the resemblance in any event is 
marvelous. 
This resemblance is no longer marvelous, when we know that 
in both cases we are talking of beds of the same age. 
JupitH RivER FORMATION 
Lance FORMATION 
Judith River Basin, Montana 
Lepidotus occidentalis 
Myledaphus bipartitus 
Accipenser albertensis 
Diphyodus longirostris 
Scapherpeton tectum 
Ischyrotherium, cf. antiquum 
Trionyx foveatus 
Adocus lineolatus 
Compsemys obscurus 
Compsemys victus 
Champsosaurus 
Crocodilus humilis 
Troodon formosus 
Deinodon horridus 
Aublysodon mirandus 
Paronychodon lacustris 
Zaphalis abradus 
Deinodon explanatus 
Deinodon cristatus 
Deinodon hazenianus 
Ornithomimus altus 
Palaeoscincus costatus 
Trachodon mirabilis 
Converse County, Wyoming 
Lepidotus occidentalis 
Myledaphus bipartitus 
Accipenser albertensis 
Diphyodus longirostris 
Scapherpeton tectum 
Ischyrotherium, cf. 
quum 
Trionyx foveatus 
Adocus lineolatus 
Compsemys obscurus 
Compsemys victus 
Champsosaurus humilis 
Crocodilus humilis 
Troodon formosus 
Deinodon horridus 
Aublysodon mirandus 
Paronychodon lacustris 
Zaphalis abradus 
Deinodon explanatus 
Deinodon cristatus 
Deinodon hazenianus 
Palaeoscincus costatus 
Trachodon mirabilis* 
anti- 
* Hatcher, Annals of the Carnegie Museum, I, No. 3, p- 382. 
Hell Creek, Montana 
Lepidotus occidentalis 
Diphyodus sp. ? 
Scapherpeton tectum 
Trionyx foveatus 
Adocus lineolatus 
Compsemys obscurus 
Compsemys victus 
Champsemys 
Crocodilus sp. 
Ornithomimus altus 
Palaeoscincus sp. 
Trachodon sp. 
In what has been written above the endeavor has been to prove 
from the words of the vertebrate paleontologists themselves the 
identity of the Judith River and Lance formations. Knocking 
from beneath the structure so elaborately reared the weak and inef- 
fective stratigraphic props, the entire edifice must fall. Either 
the beds are identical in age, or vertebrate paleontology has no 
place in stratigraphic geology, and non geologia sine paleontologia . 
becomes non paleontologia sine geologia. ‘That they are, however, 
of the same age is the irresistible conclusion to which we come. 
Whether they are of Cretaceous or Tertiary age is beside the ques- 
tion at this place, although the views and opinions of the writer as 
to their early Eocene Tertiary age have been expressed in another 
part of this paper. 
