Variation in epidermal color of na jades. 263 



Observation on Sex-Correlative Coloration as Related to Epidermal 

 Color. (13 shells) 

 Older males have warm reddish brown colors; in youth, lighter 

 yellows and olives are representative. Females have a greater 

 tendency to blacken, and have darker colors throughout life. 



5 . — Symphynota costata 



SIMPSON RIDGEWAY 



Yellowish Green Buffy Citrine 



Tawney " Brownish Olive 



Brownish Bister, Chestnut, Mars Brown, Prouts 



Bi'oWn, Mummy Brown. 



Distribution of Colors in Upper Ohio Drainage and L. Erie 

 (68 shells). 



Bister 20% 



Brownish Olive 20% 



Buffy Citrine.. '. 20% 



Chestnut 20% 



Mars Brown 20% 



Distribution of Colors as a Whole in Upper Ohio Drainage 

 and L. Erie (47 shells.) 



Warm Sepia.... 30% 



Brownish Olive .^ 20% 



Buffy Olive .....20% 



Mummy Brown ,. 20% 



Bister ^ 10% 



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



Alle'nv Alle'ny Ohio Monong Beaver 

 Tribs. River River River Tribs. 



Warm Sepia 50% 20%.... 25%. 



Brownish Olive ....12 %......2o% 25 % .50% 37 % 



Buffy Olive , 12 %......2o%......50%......25 %--25% 



Mummy Brown ..". 12% 20% 25% 



Bister i2%......2o%......25%- 13% 



Distribution of Colors as a Whole in L. Erie (2 1 shells) . 



Buffy Citrine --40% 



Chestnut .:. 20% 



Mars Brown . . 20% 



Prouts Brown... ....10% 



Mummy Brown 10% 



Distribution in L. Erie — Localities. 



La Plaisance Presque 



Bay Isle 



Buffy Citrine '. 25%.. 



Chestnut .-'. --25% 5o% 



Mars Brown... .'. 25% 25% 



