(17a) 



Table III. 

 Coefficients of correlation for line 30. 



Ancestral generations- 

 1. 2. 3. 4. 



Character. (755 ind.) (754 ind . ) (744 ind.) (693 ind.) 



Spine number. .082 ± .024 .034 ±.024 .009t.025 .007±.026 



Shell size. .253 ± .023 .026 ±.025 .012*. 025 .019±.026 



Shell form. .062 ± .025 -.045 ±.025 -.056±.025 -.011*. 026 



Mouth size. .024 t .024 .013 ±.025 -.033t.026 -.056±.026 



Mouth form. .066 ± .024 -.043 ±.025 .066±.026 -.008±.026 



