CORRELATED VARIABILITY. 61 



Example. Absolute difference between dextral (d) and 

 sinistral (s) lateral edges (L) of carapace of right-handed 

 fiddler-crabs Gelasimus pugilator (Yerkes, 1901; Duncker, 

 1903)' 



d=Ld-L s : -10 1 23 

 /: 1 63 310 23 3 



310X 1 + 23X2 + 3x3 = 365, ^(/0 = 336. 

 l, 2<j") = \, n=400. 



336X365-1X1_ 122639 

 400X366 " ~ 146400 



