The frequency of each of these f 

 at different depths and temper 

 tables on page 541 and in Fig. 4. 



•types of asymmetry 



the numbers in parentheses represent the actual cases, the 

 other numbers being the percentage of the total number 

 of genera in which the feature under consideration is 

 found. This last is given in parentheses at the head of 

 each column. 



