1883.] “ The Plains” of Michigan. 249 
of the sub-order which exhibit the true sectorial tooth of the 
upper series, as it exists in the Carnivora, and the genus Didymic- 
tis has the dental formula of Canis above. Miacis has the formula 
of Canis below, but that of the superior series is unknown. It 
would not be surprising if it should turn out to be that of Am- 
phicyon. These animals are abundant inthe Middle and Lower 
Eocenes of North America. 
10: 
“THE PLAINS” OF MICHIGAN. 
BY PROFESSOR V. M. SPALDING, 
F the northern central portion of the lower peninsula of Michigan 
there extend through several counties large tracts designated 
on some of the maps as “barrens,” but uniformly spoken of as 
“the plains” by people living upon them or in their vicinity. One 
of these tracts, perhaps the most extensive, lies along the line of 
the Mackinaw division of the Michigan Central railroad and oc- 
cupies a large portion of Crawford county, extending into the 
adjacent counties on the east side and south, and including an area 
of over a thousand square miles. A similar, though somewhat 
less extensive, region of barrens or plains is intersected by the 
Flint and Pere Marquette railroad, having its center in Lake 
county, extending southward into Newaygo and northward as far 
as the Manistee river. Similar plains, of greater or less extent, are 
s to be found in this part of the State and in the northern peninsula, 
-but the two tracts already mentioned may be taken as fair repre- 
tatives. ` 
These plains lie in what is known as the “ pine belt” of Michi- 
: = and include the poorest portions of this extensive region. 
4 ir soil is a light sand, so fine that it penetrates one’s 
4 shoes as he walks over it, and when a handful is closely examined 
_ tls seen to consist almost wholly of fine grains of silica, “ good 
_ make glass of,” as is remarked by those of the inhabitants who 
- do not believe in its agricultural capabilities. Nevertheless, these 
Plains are by no means a desert. They support quite a variety of 
Vegetable life, and one experiences no feeling of loneliness as he 
travels over them. On the contrary, wherever they have escaped 
destructive action of fire, the smooth, gently undulating 
groves of scrub pine, through which the eye has 
extended range in every direction, produces a pleasing impres- 
O l with its 
an 
