A LARGE COLONY OF FOSSIL CORAL 
109 
yard. Taking the more conservative area of the colony, given 
above as nearly 2000' square feet, there would be a population in 
this social group of over five and three quarters million in- 
dividuals. The problems of food supply, sanitation, and so forth, 
in such a social organization must have been great but they were 
successfully met. Truly, as has been said, “the coral reefs of the 
Silurian were the cities of those days. ’ ’ 
Paleontological Laboratories, 
The State University. 
