14 PALZONTOLOGY OF NEW-YORK. 
CHAZY LIMESTONE. 
The lower part of this rock, which can be seen resting upon the preceding mass, presents 
an aggregation of fragments of crinoidal remains, corals and shells ; showing conclusively 
that at this early period the sea was as well fitted for the production and support of living 
organisms, as at any subsequent period. It is true the species are not exceedingly numerous ; 
neither was the period of their duration very long. Still it is clearly evident that this portion 
of the ancient ocean, at least, swarmed with animal life in some of the lowest conditions of 
organization. In none of the subsequent groups do we find a more perfect crinoidal lime- 
stone, or one composed in greater proportion of the comminuted exuvia of these and other 
forms of zoophytic existence. Scarcely even do we find so great a number of individuals 
of any species, as can be obtained of the Maclurea upon the weathered surface of the 
stratum peculiar to that fossil. In vain shall we look for similar examples of so large a shell 
as this occurring in such incredible numbers, that several thousands may be counted in the 
space of a few rods; and in no subsequent rock can we find even the Bracuropopa in 
greater abundance than at this period, when entire strata avere composed of them. In truth 
we are almost led to conclude that this period was more favorable to the rapid development 
of organization, than most of the subsequent ones ; and thus at this primeval epoch, in 
which we have just witnessed the dawn of vitality, and might have expected a gradual 
ushering in of living forms, we find ourselves suddenly among myriads of extinct animals 
of all stages of growth and development. This epoch, like every subordinate one, has its 
peculiar and typical forms; forms which appear, thrive, and flourish for a time, and are 
never seen at subsequent periods ; and although these forms may be fewer in the present 
than in some other cases, they are nevertheless sufficient for an example on which to base 
a hypothesis concerning the creation and extinction of the successive races which have 
existed upon the earth. We find here also some forms which appear to claim an obscure 
place among their associates, but which become in succeeding periods more prominent and 
numerous, and therefore better entitled to our consideration. 
From the interest naturally attached to the forms of this early period, I have figured all 
that could be decided with accuracy ; leaving, no doubt, others to find a place hereafter. 
Indeed I think there is scarcely another portion of our series that offers a better field for the 
paleontologist, than the lower limestones which are so well developed along the valley of 
Lake Champlain, the Mohawk valley, and the Black river. Few points only have been 
examined, and these with less attention and less time than could be desired to present any 
thing like a complete exhibition of their fossil contents. 
