14 PALEONTOLOGY OF NEW-YORK. 



CHAZY LMESTOXE. 



The lower part of this rock, which can be seen resting upon the preceding mass, presents 

 an agoregation 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 Brachiopoda in 

 greater abundance than at this period, when entire strata were 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 sidjsequent 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 v/hich 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 anotiier portion of our series that offers a better field for the 

 palajontologist, than tlie 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. 



