Genera of order “"monothalamids"”

Arnoldiellina

Test free, monothalamous, fusiform, <300 um in length and <70um in width;organic wall transparent from 2to7um in width, thicker around the aperture. The single aperture is funnel-shape with a tubular internal extension. Multinucleate cytoplasm (up to 11 nuclei); granular, in constant rapid movement. Reticulopodes very active with rapidly forming reticulopodial network and fast moving granules. Specimens emit GAF (green autofluorescence), which disappeared with fixation.

Astrammina

Test free, large, up to 6.5 mm in diameter, in the form of a single spherical or flattened polygonal chamber with one to five narrow stolon-like arms radiating in various directions but usually in nearly the same plane and the longest ones commonly very flexible, may also have fragile conical projections and may produce rounded buds; protoplasmic body enclosed in a thick tripartite theca with a single oral region.

Bathyallogromia

Test monothalamous, almost spherical, 140–450 mm in diameter; wall transparent, proteinaceous, with smooth outer surface devoid of agglutinated grains; single aperture located in the centre of low, broad projecting region; cytoplasm light grey or greenish, containing various inclusions which often include mineral particles.

Bowseria

Test free, monothalamous, elongate, tubular, up to 2 mm in length and 0.5 mm in width; single terminal aperture without gromiids−like oral capsule; wall transparent, organic, with smooth outer surface; cytoplasm granular, white or yellow in color, without stercomata.

Capsammina

Species of Capsammina characterised by strongly flattened test dominated by 2-3 flat, parallel mica plates. Plates separated by more or less oval ring of white mortar composed of fine mineral grains and enclosing cell body. Both mortar and cell body visible though transparent plates.

Cedhagenia

Morphologically, the new genus is most similar to vellaria, notably in the presence in some specimens of a delicate, flared apertural extension. However, this structure is not as well developed as in Vellaria and the overall test shape is more lenticular. Molecular analyses indicate that Cedhagenia is not related related to Vellaria but most closely related to Ovammina.

Conqueria

Test free, monothalamous, elongate, tubular, up to 1000 mm long and 50 to 100mm wide with a simple aperture at the end of a short terminal neck.Wall very ¢nely agglutinated with a very smooth, non-re£ective outer surface. Cytoplasm without stercomata.

Gloiogullmia

Test elongate ovate to sausage-shaped, up to 2mm in length. Wall of two more or less separated proteinaceous membranes, single aperture, cytoplasm with numerous inclusions.

Leptammina

Test free, monothalamous and more or less spherical, up to 2 mm diameter. Wall delicate, flexible, with inner organic layer overlain by fine, loosely agglutinated mineral grains. Single prominent circular aperture, which may protrude slightly from the test surface. Cell body with well-developed peduncular sheath.

Marsipella

Elongate agglutinated test, up to 6mm in length; sand grains, sponge spicules or tests of other foraminifers are incorporated in the agglutinated wall.

Nellya

The genus differs from Saccammina and Leptammina in the shape of the test /elongate rather than approximately spherical) and the presence of a nipple-like apertural structure, which is quite unlike the simple round opening that characterizes these two genera.

Notodendrodes

Large agglutinated test consisting of a bulbous central area of which a branching system of holdfasts emerges. Bulb and holdfasts are buried in the mud with a vertical stalklike portion projecting above the surface and ending in an arborescent and flexible structure.

Psammophaga

Pyriform to ovoid test, wall of thick transparent flexible matrix with a thinner outer agglutinated covering, terminal simple aperture.

Rhizammina

Test consists of complex system of fine, branching tubules of even diameter. Test wall simple; agglutinated particles argillaceous. Stercomata (faecal pellets) accumulate within tubules.

Shinkaiya

The new genus resembles species of the genus Syringammina, in particular the type species Sy. fragilissima. The genera are similar in the general shape and construction of the test, which consists of a framework of bar-like elements, forming a tightlymeshed, often reticulated structure. The main morphological difference between the new genus and Syringammina is the nature of the test wall. In Syringammina, the wall is brittle, with a smooth inner surface, and consists of ‘tightly cemented xenophyae’ (Tendal, 1972). These comprise mainly fine sand grains and small foraminiferan tests in Sy. fragilissima. Shinkaiya, on the other hand, is characterized by a relatively thick wall that is soft rather than brittle, and consists mainly of clay-sized sediment particles.

Syringammina

The test is constructed by numerous tubes of tightly cemented xenophyae. The tubes are arranged in a radiating manner, single tubes being connected with other tubes by side branches. The xenophyae are restricted to the tube walls, and only granellare and stercomare are found in the interior.

Toxisarcon

Cell body large (up to several centimeters diameter), either covered by agglutinated test or entirely naked and resembling an amoeba. Where present, test is free with central inflated region giving rise to several branches that generally taper and multifurcate terminally. Test wall agglutinated with little particle selectivity and poorly cemented.

Vellaria

Monothalamous test, characterised by the development of a flared, conical or trumpet-shaped apertural structure which apparently serves to attach the test to small sand grains.