452 
TRANS. OF THE ACAD. OF SCIENCE. 
Fig. 2 6.—Same, surface without cells magnified. 
« 3.—Polypora es umardii. 
«3 a.—Reverse ed 
3 b.—Medallion hich niisghttied (ideal). 
Pirate XVII. 
Fig 1.—Semicoscinium rhomboideum. 
1 a.—Fenestrules enlarged. 
“1 d.—Cell structure (ideal). 
“ 1 ¢.—Terraced appearance of cells broken iy near cl 
“« 1f—Fig. of the same. 
“ 9. Flustra spa’ 
“ 2a.—Encrusting auction on. another fossil. 
“* 26, 2c.—Enlarged views of structure 
cc 
3.—Flustra tuberculata, rat. size. 
ified 
