276 TIUv AMERICAN MIDLAND NATURALIST 



Observation on Sex-Correlative Coloration as Associated with Epider- 

 mal Color. (140 shells) 

 Young males are yellow green with maturity becoming brownish 

 green. Young females are Buffy Olive in color, with age becoming 

 a greenish gold, (Olive Lake.) ^ 



12 — Lampsilis ovata 



SIMPSON RIDGEWAY 



Greenish Olive ochre 



Greenish yell6w Brownish Olive, Colonial Buff. 



Brownish Buffy Olive, Mars Brown, Bister, Saccardos 



Umber, Buffy Citrine, Ecru Ol've. 



Distribution of Colors as a Whole in Upper Ohio Drainage and 

 L. Erie (214 shells). 



Ecru Olive 20% 



Buffy Olive..... ;...... .-20% 



Brownish Olive 20% 



Colonial Buff".. ^ :.. 20% 



Buffy Citrine 20% 



Distribution of Colors as a Whole in the Upper Ohio Drainage 

 (188 shells). 



Ecru Olive 20% 



Buffy Olive. 20% 



Olive Ochre ^ 7. . 20% 



Brownish Olive 20% 



Bister -io% 



Saccardos Umber.... ...^ ...10% 



Distribution of Colors as a Whole in the Upper Ohio Tributaries. 



Ally AU'y Ohio Ohio Beaver Beaver 



Tribs. River River Tribs. River Tribs. 



Ecru Olive.. 25% 25% 20% 25% 12% 



Buffy Olive ..25% 25%--25% 20% 25% 12% 



Olive Ochre .7 20% 50%. 25%--20% 50% 25% 



Brownish Olive 25 %--25 %- 25 % 20% --37 % 



Bister .......:. 5%...... : 12% 



vSaccardos Umber 20% 



Distribution of Colors as a Whole in L. Erie (26 shells). 



Colonial Buff... 30% 



Buffy Olive 30% 



Brownish Olive 20% 



Buffy Citrine... 10% 



Mars Brown. 10% 



Distribution in L. Erie — localities, and Chautauqua Lake. 



La Plaisance Cedar Presque Chautauqua 

 ^ Bay Point Isle Lake 



Colonial Buff 50% 50% .50% 



