VARIATION IN EPIDERMAL COLOR IN NAJADES. 265 



6. — Anodonta grandis 



SIMPSON RIDGEWAY 



Greenish brown Yellowish Olive, Olive Green 



Brownish green Brownish Olive, Ecru Gl4ve « 



Other Colors: 



Buflfy Citrine, Varley Green, Straw 



Yellow, White. 



Distribution of Colors as a Whole in Upper Ohio Drainage and 

 L- Erie (119 shells). 



Brownish Olive , _.. 40% 



Yellowish Olive 20% 



Olive Green '. ..: 20% 



Ecru Olive ' 10% 



Buffy Citrine 10% 



Distribution of Color as a Whole in Upper Ohio Drainage (97 



shells) . 



Brownish Olive... _ 40% 



Olive Green 20% 



Saccardos Olive. 20% 



Ecru Olive : ■....10% 



Buffy Citrine :.. 10% 



Distribution of Colors in Upper Ohio Tributaries etc. 



Allegheny Beaver Mgnong. 

 Tribs. Tribs. Tribs. 



Brownish Olive 50% 25% - 



Olive Green.- 25% 25% 



Saccardos Olive 12%. 25% 



Ecru Olive 25% 25%. 



Buffy Citrine 12%... 25%^ 



Mummy Brown — -50% 



Distribution of Colors as a Whole in L. Erie and by localities. 



As a La PUisance Cedar Presquc 

 Whole Bay Point Isle 



Brownish Olive 30% -25% 25% .25% 



Ecru Olive" 30%-.. - 50%-. 25% 



Varley Green.. 20%: .25% 



Straw Yellow :.. .10% 50%.. 25% ...25% 



White ..: 10% 25% .-- 



Deductions from Tables of Percentages and PI. III. 



The Iv. Erie shells ,may be distinguished from those of the Upper 

 Ohio by the abundance of yellowish and greenish yellov^r tints, those 

 of the latter being Brownish or Yellowish Olive. 

 In the Upper Ohio Drainage. 



A darkening descending the Allegheny was observed in the 

 scanty material at hand. This is more evident in French Creek 



