216 The Mesozoic Series of New Mexico. — Marcou. 
ice stretched across the continent from Newfoundland and 
cape Cod to Vancouver island. 
During the second and last great epoch of glaciation, wh^n 
the terminal moraines of the northern United States, Mani- 
toba, and the Saskatchawan region were accumulated, the 
extent of the ice-sheet in Pennsylvania, New Jersey, and New 
England appears to have equalled or exceeded that of the 
earlier ice-sheet ; but within the Mississippi basin it fell short 
of the earlier limit by a belt whose maximum width is about 
two hundred and seventy-five miles. The northwestward con- 
tinuation of the outer terminal moraines of this epoch, beyond 
the north line of Dakota, is believed to coincide approximately 
with the continuation of the Coteau du Missouri and with the 
Neutral and Beaver hills, crossing the South and North Sas- 
katchawan rivers respectively about three hundred and twenty- 
five miles and two hundred miles east of the Rocky mountains. 
The thickness of this later ice-sheet upon the area of Hudson 
bay and eastward was apparently as great as that of the 
earlier glaciation, but westward from Hudson bay it dimin- 
ished in thickness more rapidly, probably having a depth of 
about 6,000 feet over Reindeer and Winnipeg lakes, and termi- 
nating east of the Hand, Cypress, and Sweet Grass hills, 
which had been islands surrounded by ice in the previous 
glacial epoch. As president Chamberlin has suggested, the 
great lakes of British America, namely, Winnipeg, Reindeer, 
Athabasca, Great Slave, and Great Bear lakes, with the Mac- 
kenzie river, may be found to sustain the same relationship to 
the western and northwestern boundary and terminal moraines 
of the later ice-sheet formed on the northeast part of our con- 
tinent, that has been found along its southern border in the 
United States for the great Laurentian lakes and the Missouri 
and Ohio rivers. 
THE MESOZOIC SERIES OF NEW MEXICO. 
II. 
By Jules Marcou. 
Dr. Newberry was sent again to New Mexico in 1859, as 
geologist of Capt. Macomb's exploring expedition to the Grand 
and Green rivers of the great Colorado. A short resume of 
this second expedition was published at once in the Amer. 
Jr. Sei. vol. xxviii, p. 298, September, 1859, under the title : 
"Dr. Newberry's late explorations in New Mexico — he shows 
