


' | 
CRETACEOUS AND TERTIARY—GENERAL ARRANGEMENT. 149 
Nebrascana, and Rostellaria Americana. As localities of this group, Dr. 
Hector mentions doubtfully the Elbow of Battle River, and the lower part 
of the section at the Roche Percée. The latter may now be included cer- 
tainly in the Lignite Tertiary. The former is not fully described, and no 
fossils appear to have been obtained from it. 
Distribution of Cretaceous Subdivisions. 
362. Taking into account, the whole of the information accessible 
on the Cretacéous formation in the interior region of British North 
America, and the general contour and character of the country; the limits 
of some of its members, and the area they cover, may be laid down with 
an approach to accuracy. The western boundary of No. 4 crosses the 
forty-ninth parallel, between the 170 and 240 mile points west of Red 
River, and probably nearer the latter than the former. Thence it runs 
west-north-westward, and passing north of the Lignite Tertiary beds dis- 
covered by Prof. Bell near Dirt Hills, becomes nearly identified with the 
edge of the Missouri Coteau, before reaching that part of it called the 
Thunder Breeding Hills on Palliser’s map. Thence, after dipping south- 
ward into one or two deep bays, it reaches the Cypress Hills. A narrow 
neck of these Cretaceous rocks, may thence possibly pass round the west- 
ern escarpement of these hills, and unite with the wide area covered by 
them to the south, where they stretch from long. 109° to about long. 
910° 20’ on the Line. The strip of this formation northward of the Cy- 
press Hills, is, according to Dr. Hector’s map,* quite narrow; and north- 
ward from the Thunder Breeding Hills he has laid down the western edge 
of the rocks which I identify with No. 4, as nearly following the edge of 
the third prairie plateau—previously described,—to the North Saskat- 
chewan. South of the Wood Mountain portion of the Tertiary plateau, 
the rocks of this series, and of No. 5, have a breadth of about eighty miles 
on the forty-ninth parallel, and stretch northward in the form of bays 
and inlets into the Tertiary. Round the whole of the northern edge of 
the Missouri Coteau, the rocks of No. 5, probably cover but a narrow strip 
of ground, between the boundary indicated for No. 4 and the Tertiary to 
the south ; with, however, the exception of the locality near the Elbow 
of the South Saskatchewan, where they appear to be more important, and 
to underlie a considerable area. 
~ 363. Eastward from the edge of the third plateau, rocks of the age 
* Journ. Geol, Soc., vol. xvii. 
