130 The Winooski or Wakefield Marble of Vermont. (February, 
Most of the layers are not fossiliferous, and in few are fossils 
abundant. It may be true that fossils are really more common 
than they seem to be, for they only occur as casts, and, with the 
exception of the Algz, these are rarely visible except when the 
surface of the stone has weathered so as to leave them in relief, 
and of course this only happens occasionally. Near Burlington, 
where the stone is extensively quarried for building purposes, 
some of the layers exhibit abundant casts of Algæ together 
with mud cracks, ripple marks and other evidences of shallow 
water formation. Farther north, at Georgia, and still more to 
the north at Highgate, various trilobites and Mollusca have been 
found of the genera Paradoxides, Conocephalites, Camerella, 
Orthisina, Obolella, &c. (see No. 4 above). The dolomitic portion 
of the beds constitute what has long been known as the “ Winoo- 
ski marble,” to which I wish to call especial attention in the fol- 
lowing pages. 
The beds of “ marble” appear first one or two miles north of 
Burlington and extend in a somewhat interrupted series north 
through St. Albans and end between that place and Swanton. 
Some of the layers are quite distinct from the red sandrock 
proper, others pass into it by imperceptible gradations. Ordina- 
rily the marble beds are far less siliceous than the main bulk of 
the sandstone, often containing only one-seventh as much silica 
as that usually contains, or even less, but they are always much 
harder than ordinary marble. Analyses of the marble have been 
made but cannot be of great value when applied to the whole 
mass because the relative proportion of the substances compos- 
ing it is extremely variable. 
Identical results weuld scarcely be obtained from analyses of 
any two specimens taken at places a little distant from each other. 
Silica is always present, usually about ten per cent, lime carbon- 
ate forms from thirty to forty per cent, and magnesia carbonate 
about the same, while iron and alumina form a smaller portion of 
the mass. 
No fossils had been discovered in this portion of the formation 
until a few years ago, when on looking over a pile of sawn frag- 
ments—refuse from the mill at Swanton—I noticed two or three 
pieces which contained evident fossils. These were afterwards 
identified by Mr. Billings as Sa/terella pulchella, described by him 
from the Straits of Belle Isle, and not hitherto known from Ver- 
