12 



Prof. W. F. R. Weldon. Certain 



[Mar. 3 y 



Table III. — Length of Post- spinous Portion ( ps) for every observed 

 Valne of Total Carapace Length, (c) in Southport. (800 indi- 

 viduals.) 



M c = 248 '31 ; Q c = 3 -96. M ps = 180 '29 ; Q,^ = 3 '65. 



Length of 

 c. 



Mean associated 

 length of ps. 



Length of ps when 

 r = 0-85. 



1 



Difference 

 observed, ps. 



over 256 



188 -70 



189-43 



-0-73 



256 



186 -50 



186 -30 



+ 0-20 



255 



185-37 



185 -36 



+ 0-01 



254 



185-48 



184 -61 



+ 0-87 



253 



183 -65 



183 -83 



-0-18 



252 



182 -84 



183 -08 



-0-24 



251 



182-37 



182-33 



-0-04 



250 



181-43 



181 -58 



-0-15 



249 



181-27 



180 -83 



+ 0-44 



248 



179 -89 



180 -05 



-0-16 



247 



178-57 



179-30 



-0-73 



246 



177 -69 



178 -55 



-0-86 



245 



178-45 



177 -77 



+ 0-68 



244 



176-81 



177 -02 



-0-21 



243 



176 -66 



176-27 



+ -39 



242 



176 -76 



175 -49 



+ 1-25 



241 



174-81 



174 -74 



+ 0-07 



under 241 



173 -54 



173-13 



+ 0-41 



Table IV. — Value of Total Carapace Length for every observed Length 

 of Post-spinous Portion of Southport. (800 individuals.) 



Length of 

 ps. 



Mean associated 

 length of c. 



Length of c when 

 r = 0-85. 



Difference 

 observed, e. 



over 189 



258 -38 



258 -38 



o-oo 



189 



254-62 



256 -36 



-1-74 



188 



255-61 



255 -42 



+ 0-19 



187 



254-93 



254-51 



+ 0-42 



186 



252 -92 



253 -57 



-0-75 



185 



252 -43 



252 -66 



-0-23 



184 



250-80 



251-75 



-0-85 



183 



250-67 



250 -80 



-0-13 



'182 



250 -31 



249 -89 



+ 0-42 



181 



249 -18 



248 -95 



+ 0-23 



180 



247-16 



248 -04 



-0-88 



179 



247 '28 



247-13 



+ 0-15 



178 



247-91 



246 -91 



+ 1-00 



177 



244-33 



245 -28 



-0-95 



176 



243 -51 



244 33 



-0-82 



175 



243 -42 



243 -33 



+ 0-09 



174 



241 -20 



242 -48 



-1-28 



173 



241-48 



241-57 



-0-09 



172 



241-16 



240 -66 



+ 0-50 



under 172 



238-78 



240 -05 



-1-27 



