234 "^H^ AMERICAN MIDLAND NATURALIST 



characteristic of Chautauqua Lake.* Greater uniformity of nacre 

 color was found in this than in any other species, a fact somewhat 

 associating itself with the ubiquitous distribution of the species. 



Observation on Sex Correlative Coloration, etc. {q4 shells). 



Males — Pinkish lilac, and apparently a greater proportion of 

 white. 



Females — Pale grayish blue violet — slightly more pearl blue. 



12. — Lampsilis ovata 



SIMPSON RIDGEWAY 



Silvery White 



Bluish white Pearl blue. Pale Grayish Blue Violet 



Pink Light Pinkish Lilac, Pale Purplish Vinaceous. 



Distribution of Colors as a Whole in the Upper Ohio Drainage 

 and Lake Erie. (214 shells). 



Pearl Blue, etc 20% 



White, etc 20% 



Light Pinkish Lilac, etc - 30% 



Pale Grayish Blue Violet, -etc 11% 



Pale Purplish Vinaceous, etc 19% 



Distribution of Colors as a Whole in Upper Ohio Drainage. 



(188 shells). 



Pearl Blue, etc 19% 



Light Pinkish Lilac, etc.... 25 % 



White, etc - 19% 



Pale Grayish Blue Violet, etc 19% 



Pale Purplish Vinaceous, etc 18 % 



Distribution in Upper Ohio Tribs., etc. 



Alle'ny Alle'nv Ohio Ohio Beaver Beaver 



Tribs. River River Tribs. River Tribs. 



Pearl Blue, etc 20% 22% 14% 10% 35% 22% 



Light Pinkish Lilac, etc 25%......24% 34% --4i% 4% 4o% 



Whfte .....20% 22% 25% 13% 16% 16% 



Pale Grayish Blue Violet, etc 17% 15% 12% 25% 16% 15% 



Purplish Vinaceous, etc .18% 17% 15% 11% i9% 7% 



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



Pearl Blue, etc 24% 



Light Pinkish Lilac, etc. 23 % 



White, etc 22% 



* My observations on all lake specimens of this species correspond with 

 those of Baker concerning it in Oneida Lake, N. Y. Baker, F. C, The 

 Relation of Mollusks to Fish in Oneida Lake, Tech. Pub. No. 4. N. Y. 

 State College of Forestry, Syracuse, 1916. p. 41. 



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