Genus Rotaliammina


Rotaliammina Cushman, 1924, emended Brönnimann and Zaninetti, 1984


Cushman, 1924, p. 11. Emended Brönnimann and Zaninetti, 1984, p. 74


Description:  Test rotaliform, attached by the ventral side, all chambers visible from above, only those of the last formed coil from below; chambers numerous with thick arenaecous walls of matted spicules, the area between softer and somewhat flexible; aperture ventral along the growing edge of the test.


Emended description: Test normally attached; trochospiral, adult growth form watch-glass like, with peripheral flange; wall agglutinated, imperforate, single-layered; aperture single, interior marginal at axial end of sac- or mushroom- or petal-like chamber as seen umbilically, axially directed.



Rotaliammina squamiformis (Cushman and MCulloch, 1939)

Rotaliammina squamiformis Cushman and MCulloch, 1939, p 108, fig 4a, b, c; Loeblich and Tappan, 1964, p. 265, fig. 174.2; McGann, 2007, p. 64, pl. 9, fig. S.


Type description: Test small, scale-like, dorsal side convex, ventral side concave, periphery rounded to subacute; chambers distinct in the earlier whorls which have 8-10 chambers, higher than broad, in the adult with the chambers becoming lower than broad in the whorl and much reduced in number, on the ventral size triangular, often with slightly raised liplike portion over the aperture; sutures curved, little if at all depressed on the oral side, ventrally radial or slightly tangential, often somewhat sigmoid; wall finely arenaecous, smoothly finished, with much cement giving a yellowish-brown color, especially in the early whorls; aperture a low opening at the inner end of the margin of the ventral face of the last-formed chamber. Diameter 0.25-0.30 mm; height 0.10 mm.


Distribution: The type specimen of Rotaliammina squamiformis is from a 3.6 m depth off Milwaukee Pier, Port Angeles Washington. This species in not abundant but is found in South Sound, south of Anderson Island, and in Boundary and Bellingham bays


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