Turner, F. E., 1938. Stratigraphy and Mollusca of the Eocene of Western Oregon. Geological Society of America Special Papers, 10.
New Species-Group Names:
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comstockensis Turner, 1938. p. 68. pl. 15. f. 5.
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umpquaensis Hendon in Turner, 1938. p. 69. pl. 15. f. 1. 2.
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warreni Hendon in Turner, 1938. p. 68. pl. 15. f. 3. 4.