No. 200.] 
285 
Water Limes. — No fossils; layers thin, of a drab colour. I found in 
this series, one specimen of the form which common salt assumes in 
crystalyzing upon a liquid surface; they are extremely common on Nine 
Mile creek, in Onondaga. They are called by the French, marne en 
retraite. The water limes, and the limestone above it, have furnished all 
the calcareous tufa of Oneida and Herkimer. 
Upper Limestone. — This mass forms the elevated plain, as it were, to 
the south of the Mohawk. This limestone is well characterized by its 
fossils. The species which have given rise to the greatest number of 
individuals, are Cytherina Leptoena depressa, Leptcena punctulifera, 
Orthis affinis, O. concentrica, O. resembling the hastata, Pentamerus 
knightii, Certocerus Cyathophyllum ceratites, Columaria alveolata, 
tentaculites, Asaphus micrurus and Calymene bufo. 
W7tite Sandstone. — Characterized by large species of Orthis and Del- 
thyrus. 
Pyritiferous Rock. — Dark coloured, coarse arenaceous shaly mass, 
rises in broad ridges upon the calcareous platform, the waters which 
flow^ north and south dividing upon this mass. 
The products of all that part of the third district, examined, with 
some important exceptions, are more immediately connected with the 
first wants of man, those of agriculture, building, &c. and with his 
highest, those which subserve science, rather than with that kind of mi- 
neral wealth dependant upon mining, the object commonly supposed of 
the great utility of a geological survey. 
Though the class to which the rocks of the district belong, has been 
for some time known to a few of our geologists, yet it is only within a 
few years, that we have been able definitely to connect them with the 
European series. Until about eight years since, when Mr. Murchison 
commenced the examination of a part of Wales, nothing was with cer- 
tainty known in Europe, of a like series; and from the delay in the 
publication of his work, being yet in the press, we are led to infer that 
he has experienced no ordinary difficulty in restoring the rocks to their 
original order of arrangement. What little he has published, from time 
to time, has been just sufficient to excite our desire for more informa- 
tion, and to fully establish in our minds, the perfect identity as to the 
general causes which gave rise to similar, if not almost identical, produc- 
tions, separated from each other by a distance of over 3,000 miles. 
What is there obscure, is, in the third district, evident, the derangement 
being but partial and of great importance to the elucidation of the dis- 
