[Montfort 1808 emend. Brönnimann and Whittaker 1980]: Remarks. – The test of the genus Reophax, as emended above, differs from that of Hormosina Brady, 1879, in having an incurved early portion and ventricose asymmetry of the adult chambers as seen in lateral view. The type-species of Hormosina, H. globulifera Brady, 1879, originally described by Brady from deep waters of the Atlantic and Pacific Oceans, is characterized by linearly arranged (occasionally irregularly disposed), globular, thin-walled, smooth-surfaced chambers (or rarely a single chamber) and a rounded terminal aperture produced on a distinct neck; the chambers, furthermore, are radially symmetrical. The generic differentiation between Reophax and Hormosina has in the past been unclear. It was dealt with by Brady (1884, Challenger Exped. 1873-1876, Rept., Zool., vol. 9, pt. 22, p. 325) when he wrote that … “The genus Hormosina comprehends the moniliform section of the Trochammininae and occupies the same position in the group that Reophax takes amongst the rougher Lituolidae. Under ordinary circumstances, there is no difficulty in distinguishing the Hormosinae from their larger Lituoline isomorphs, by their thin walls and smooth, almost homogenous tests, and amongst the smaller species by their regularity and symmetry of form”. Brady, however, still placed forms with radially symmetrical chambers in Reophax (a typical species being R. dentaliniformis (Brady) [Lituola (Reophax) dentaliniformis, 1881]), whereas, work by one of us (Brönnimann, 1980, Pal. Zeitschr., vol. 54, pp. 67-89) on Recent radially-symmetrical “reophaxes” from the Campos Shelf of Brazil, has shown that Brady’s criteria cannot be used in all cases to separate the two genera. Instead, the ventricose chamber asymmetry and initial curvature of the test, features highlighted in our emended generic diagnosis of Reophax (discussed further on p. 266, below [see Obliodolina Brönnimann and Whittaker, 1980]), are much more reliable parameters. Wiesner (1931, in: Drygalski, Deutsche Südpolar-Expedition 1901-1903. Berlin & Leipzig: de Gruyter, p. 89) arrived at similar conclusions to ourselves, but in spite of his observations, he still used the consistency of the wall as his main distinguishing feature.

As both Ginesina Bermúdez and Key, 1952, and Nodulina Rhumbler, 1895, have straight, linear tests and radially-symmetrical chambers, they are synonymized with Hormosina, instead of Reophax as was proposed by Loeblich and Tappan (1964, in: Moore (Ed.), Treatise on invertebrate paleontology. New York: Geol. Soc. Amer., pt. C, Protista 2, vol. 1, p. C216).

Proteonina fusiformis Williamson, 1858, type-species of Proteonina Williamson, 1858, from the Recent of Skye, was originally shown in side view (pl. 1, fig. 1 [see Catalogue]) to possess an asymmetric ventricose ultimate chamber which gradually tapers to a rounded terminal aperture without a neck; the chamber is round in transverse section. There is some controversy as to whether this specimen is monothalamous or is subdivided. Williamson’s figure does not appear to show sutures, but Loeblich and Tappan’s (1955, Smithsonian Inst., Misc. Coll., vol. 128, no. 5 (publ. 4214), p. 7, pl. 1, figs. 2, 3) lectotype, together with a specimen illustrated from Norway and referred by Höglund (1947, Uppsala, Univ., Zool. Bidrag, Bd. 26, pl. 4, fig. 21) to this species, clearly do. After re-examining Williamson’s material we have no hesitation in stating that Proteonina is a junior homonym of Reophax.

The genus Sulcophax Rhumbler, 1931 (type-species S. claviformis Rhumbler, 1931), from deep water off Antarctica, is characterised by a linear test, heteropolar chambers and a sulcus-like depression across the terminal face in which an elongate apertural slit is situated. It is accepted as being distinct from Reophax by Loeblich and Tappan (1964, op. cit., p. C217, tfs. 128(8a, b)). Its chambers, although rounded in transverse section, are not radially symmetric, but through the development of a sulcus, dissymmetric. Hence, Sulcophax, though possessing a straight linear test, cannot be placed in Hormosinella and is distinct.

Glaucoammina Seiglie and Bermúdez, 1969, type-species Reophax trilateralis Cushman, 1935, from the Caribbean shelf seas, differs from Reophax in having a completely enrolled early stage. Oblidolina Brönnimann and Whittaker, 1980, type-species Reophax arctica Brady, 1881, from Arctic waters, lacks the incurved initial curvature of the test as seen in Reophax and is strongly laterally compressed (see p. 267, below [see Oblidolina Brönnimann and Whittaker, 1980]).

Finally, there are certain Recent hormosinid species, previously referred to Reophax, such as R. scottii Chaster, 1892, from shallow water off the coasts of the British Isles, which exhibit an ordered, tile-like arrangement of the quartz flakes making up the single-layered, imperforate wall (see Murray, 1971, An Atlas of British Recent Foraminiferids. New York: American Elsevier Publ. Co., p. 17, pl. 1, figs. 7, 8). The order in which the wall is constructed might be taxonomically significant at generic level, but at present there exists no comparative study of hormosinid wall textures which considers this potentially important criterion.

Synonymy:

• Orthoceras? Brugière. – Soldani, 1795, Testaceographiae ac Zoophytographiae parvae et microscopicae. Senis: F. Rossi, vol. 1, p. 239.
• Nodosaria Lamarck. – d’Orbigny, 1826, Ann. Sci. Nat., sér. 1, tome 7, p. 251.
• Proteonina Williamson, 1858.
• Lituola Lamarck. – Parker and Jones, 1860, Ann. Mag. Nat. Hist., ser. 3, vol. 6, pp. 346, 347.
• Silicina Bornemann, 1874.
• Reophaxopsis de Folin, 1887.

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