2 74 THE AMERICAN MIDLAND NATURALIST;^ 



Observation on Sex-Correlative Coloration as related to Epidermal 



Color. (45 shells). 

 Males are Greenish- Olive in younger stages. Snuff Brown when 

 old. Females are Brownish Olive when young, becoming darker 

 blackish brown with age. 



1 1 .- — Lampsilis luteola 



SIMPSON RIDGEWAY 



Straw Colored Olive Lake 



Yellowish Buffy Olive 



Greenish yellow Ecru Olive 



Brown when old. Brownish Olive, Light Brownish Olive. 



Dristribution of Colors as a Whole in the Upper Ohio Drainage 

 and Iv. Erie (289 shells). 



Brownish Olive 30% 



Rcru Olive ^.... 20% 



Buflfy Olive...... 20% 



Olive Lake.... 20% 



Light Brownish Olive. 10% 



Distribution of Colors as a Whole in the Upper Drainage (187 

 shells) . 



Buflfy Olive 30% 



Olive Lake ....: 20% 



Brownish Olive. 20% 



Ecru Olive... '. ._., 10% 



Light Brownish Olive.. 20% 



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



Alle'ny AUe'ny Monong. Monong. Ohio Beaver Beaver 

 Tribs. River River Tribs. River River Tribs. 



Buffy blive 8% 25% 25%--25% 50%-.-io% 



Olive Lake 32 % 50% 25 % 25 % - -3o% 



Brownish Olive 4%-- - 25% 25,% 50% 



Ecru Olive .32% 25%.--50% 25% 25%- 25%- 10% 



Light Brownish 01ive.-24%......25 %... 25 % 25 %.... 



Distribution of Colors as a Whole in L. Erie (i 11 shells). 



Mars Brown 30% 



Olive Lake..... _ _ 20% ^ 



Dark Olive Buff 20% * 



Buffy Olive 20% 



Ecru Olive 10% 



Distribution of Colors in L. Erie — LocaUties. 



Conneaut La Plais- Presque Chau- Maumee 

 Lake sance Bay Isle taugua L River 



Mars Brown. ,...,... 25%.^ 



Olive Lake 25 %- 25 % 25 % 25 % 



Dark Olive Buff. 25% 50% 25%- 50% 



