1889. 1 Geology and PalcEontology. 491 
and to the Bunotheria. The former are typical members of 
the order, while though it is at yet difficult to locate the 
latter with certainty, they display no dental characters not 
found in the Creodonta. No Condylarthra have been as 
yet obtained, a fact which so far indicates the distinction be- 
tween the faunae of the Laramie and Puerco epochs. Apart 
from this, the fossils strongly resemble those of the Puerco, 
and detract nothing from the supposition which I have enter- 
tained that the latter fauna belongs to the Mesozoic series. It 
is needless to say that the position which I assumed in 1869, 
that the Laramie belongs to the Cretaceous system, and is not 
Caenozoic, is fully sustained. 
The manner in which Professor Marsh has done this work 
requires notice. The most superficial knowledge of the sub- 
ject would have shown him that the molar teeth which he has 
described as representing distinct genera belong mostly to dif- 
ferent parts of the series of the same genus, and often species, 
and not unlikely, individuals. Thus, supposing superior ante- 
riormolarsto be regarded as typical, we havethe posterior and in- 
ferior molars, andeven the premolarsofthesamegenusdescribed 
under separate generic names. In his first contribution nine 
generic names may be, with the greatest probability, referred 
to two genera. One of these is the genus Meniscoessus, 
known since 1882, and the other is not shown to be distinct 
from Chirox or Polymastodon of the Puerco fauna. Of Buno- 
theria the three genera are proposed on teeth from different 
positions in the jaws of forms which may well belong to one 
genus, and no evidence is brought forward to show how they 
differ generically from the smaller species of Sarcothraustes of 
the Puerco. This is not the way to advance science. 
Professor Marsh states that the genus Meniscoessus was 
described from a tooth which he supposes to belong to a re- 
ptile. The fact is that was founded on the molar tooth of 
the mammal to which Professor Marsh now gives, among 
others, the name Selenacodon. (See American Naturalist, 
1882, p. 830.)— £". D. Cope, 
Notes on the Origin and History of the Great 
Lakes of North America.'— Z^/i^^-^'^^O'^/^^^^ ancient course 
of the St. Lazvrence River. Previous investigations by the 
author showed that there was a former river draining the Erie 
basin and flowing into the extreme western end of Lake On- 
