152 



THE DAW2T OF LIFE. 



I 



inverted cone of carbonate of lime from an inch or 

 two to a foot in lengthy and with its point buried in 

 the mud at the bottom of the sea^ while its open cup 



Fig. 38. Archceocyathus Minganensu — a Primordial Protozoon. 

 {After Billings.) 

 (a.) Pores of the inner wall. 



extends upward into the water. The lower part 

 buried in the soil is composed of am irregular acervu- 

 line network of thick calcareous plates, enclosing 



