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ORDERS 



BELONGING TO THE FIRST CLASS. 



1st Order. Cells isolated, or else uniting in each 

 other's formation, as do the cells of a honey-comb. 



2nd Order. Cells of distinct formation, but uniting 

 together, and coalescing with the stem. 



3rd Order. Cells tubular in form, and horny in 

 substance. 



ORDERS 



BELONGING TO THE SECOND CLASS. 



1st Order. Polypi at the extremity of the Poly- 

 pidom or its branches. 



2nd Order. Articulated Polypidoms ; Polypi not 

 apparent. 



3rd Order. Inarticulated Polypidoms. 



