30 
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. 
