Genus Polymorphina


Polymorphina d’Orbigny, 1826


Description from Loeblich and Tappan (1964): Test elongate, somewhat compressed, commonly twisted; chambers biserial, early ones may be somewhat sigmoid.



Polymorphina kincaidi Cushman and Todd, 1947


Polymorphina kincaidi Cushman and Todd, 1947, p. 12, pl. 2, figs. 9, 10; Todd and Low, 1967, pl. A 25-26, pl. 3, fig. 14.


Description: Test much compressed, sides flattened or slightly concave, periphery broadly rounded, the edges very slightly keeled, initial end subarcuate to rounded, apical end contracted; chambers biserially arranged, 10-15 in the adult, increasing gradually but evenly as added; sutures distinct, flush with the surface; wall with a few weak, longitudinal costae on the flat surface near the periphery and along the rounded periphery; aperture terminal, radiate or sometimes with a fistulous growth.  Length up to 1.30 mm, breadth up to 55mm, thickness 0.20 mm.


Remarks: Although the authors did not mention it, this species is named after Trevor Kincaid, a member of the Young Naturalist Society in Seattle, in the 1890s, This society was the fore-runner of the Burke Museum of Natural History and Culture on the University of Washington campus.  The holotype of Polymorphina kincaidi is from Friday Harbor, San Juan Island, Washington.


Distribution: Rare in Puget Sound.