14 Prof. W. F. K. Weldon. Certain [Mar. 3, 



Table VII. — Mean Post-spinous Length for every observed Value of 

 Total Carapace Length. (Sheerness : 380 individuals.) 



M c = 247-33 ; Q c = 3-29, = 179'68; Q ps = 2-91. 



Length of c. 



Mean associated 

 length of ps. 



Value of ps when 

 r = 0-85. 



Difference 

 observed, ps. 



Over 251 



184-52 



184 -94 



-0-42 



251 



185 '38 



182 37 



+ 3-01 



250 



181 '07 



181 -62 



-0-55 



249 



180 -48 



181 -07 



-0-59 



248 



181-19 



180 -26 



+ 0-93 



247 



179 -03 



179 -44 



+ 0-41 



246 



178-69 



178 -62 



+ 0-07 



245 



177 '96 



177 -98 



-0-02 



244 



176 -73 



177 26 



-0-53 



243 



177 -29 



176 -51 



+ 0-78 



Under 243 



175 -53 



174-38 



+ 1-15 



Table VIII. — Mean Carapace Length for every observed Value of the 

 Post-spinous Portion. (Sheerness : 380 individuals.) 



Length of ps. 



Mean associated 

 length of c. 



Length of c when 

 r - 0-85. 



Difference 

 observed, c. 



Over 183 



253-55 



254-97 



-1-42 



183 



249 -29 



250 -56 



-0-67 



182 



248-50 



249 -59 



-1-09 



181 



249 -21 



248-60 



+ 0-61 



180 



247 -70 



247 -64 



+ 0-04 



179 



246-06 



246-68 



-0-62 



178 



245 -93 



245 -69 



+ 0-24 



177 



246 -29 



244-73 



+ 1-56 



176 - 



243-00 



243 -76 



-0-76 



Under 176 



242-75 



240 -68 



+ 2-07 



