W. M. Fontaine—Mesozoie Strata of Virginia. 25 
lower stations, and we sometimes find low areas resulting from 
a circulation of the surface winds which does not extend to the 
height of 6,000 feet. 
2. At the height of 14,000 feet the fluctuations of the barom- 
eter are quite large, but the centers of low pressure at this ele- 
vation differ in position from those at lower stations, so that 
frequently there appears to be but little correspondence between 
the movements of the wind on Pike’s Peak and the fluctuations 
of pressure at the lower stations, and we frequently find areas of 
low pressure resulting from a circulation of the surface winds 
which does not extend to the height of 14,000 feet. 
In preparing the materials for this article I have been assisted 
y Mr. Henry A. Hazen, a graduate of Dartmouth College of 
the class of 1871. 
Art. II.—Notes on the Mesozoic Strata of Virginia; by 
Wma. M. Fonraline. 
In this paper I present a summary of the results attained by 
a series of examinations, made in the Mesozoic strata of Vir- 
ginia. ese examinations have occupied the larger portion of 
my summer vacations for several years. Some of my conclu- 
sions were reached sometime ago, but as the field presents 
many difficulties in its study, and as I arrived at some unex- 
pected results, I was not willing to present them until I had 
made repeated observations, and at remote points. As I have 
been very slow myself to reach some of these conclusions, I 
must expect that others will require convincing evidence before 
accepting them. Such evidence perhaps cannot be presented 
in the limits of an article. To a fully with my material, 
whether stratigraphical, lithological, or derived from the fossil 
plants, will require an extended memoir. I hope soon to 
present this. 
he great denudation which the Mesozoic beds and the 
enclosing crystalline or Azoic rocks have undergone, the 
proneness of the former to fall into a loose incoherent mass, 
_ the covering of drift matter and clay which often conceals the 
outcrops, all unite to render the task of studying the Mesozoic 
of Virginia a very laborious and difficult one. : 
It is due to Professor Wm. B. Rogers to state that his care- 
ful and accurate observations, made in the early surveys of 
Virginia, have rendered my work very much easier than it 
would otherwise have been; much that I have observed is 
merely a confirmation of what he had already noted. He has 
_ given correctly the location, boundaries and general character 
