^l^.-'^-^ 





^^^^^4^-^ ^5>2£^' 



STRUCTURE AND CLASSIFICATION 



OF 



ZOOPHYTES. 



BY 



JAMES D. DANA, A.M., 



GEOLOGIST OF THE UNITED STATES EXPLORING EXPEDITION. 



DURING THE YEARS 



1838, 1839, 1840, 1841, 1842. 



PHILADELPHIA: 



LEA AND BLANCHARD. 



1846. 



