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Actinomma sol
Cleve, 1901
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Description - Add description
Actinomma sol:
Radial proportion of the three shells 1:2.5:9. Cortical shell thick-walled, with circular, regular, six-lobed pores, as broad as the bars. At each nodal-point is a bristle like spine, half as long as the radius, thus every pore surrounding by a corona of six bristles.
Owing to the thickness of the cortical shell, the interior shells were visible merely as faint shadows, so I am not quite convinced whether the shells are 3 or 2. If the latter be the case, the species belongs to Haliomma and is then nearest akin to H. horrida.
Diameter of the outer shell 0.09 mm, of the cellules 0.001 mm. | | Cleve 1901 | Benson, 1966, p. 132-134; pl. 2, figs. 12-13, not fig. 11
Thecosphaera sp.
Fully developed forms consisting of three concentric, latticed, spherical shells (two inner medullary shells and an outer cortical shell) joined by numerous (10-30 or more) thin, delicate, radial beams. Surface of cortical shell without main spines but with short thorns or thin conical spines located at the nodes of the intervening bars; a few tests with short thorns continuous inward as radial beams; cortical shell with relatively small, subequal, circular to subpolygonal, hexagonally-arranged pores, 10-17 on half the circumference; pores surrounded by polygonal frames; intervening bars of variable thickness but generally heavy; thickness of shell wall variable (as thick as 18 µm, generally 5-8 µm). Medullary shells widely separated from cortical shell. Inner medullary shell polyhedral with thin intervening bars separating large polygonal pores, 2-3 on half its circumference; inner joined to the outer medullary shell by 10-20 thin radial beams which arise from its surface. Outer medullary shell spherical to subspherical, with small, subequal, regularly arranged, polygonal to subcircular pores (8-14 on half the circumference) separated by thin intervening bars, with or without polygonal frames; joined to the cortical shell by 10-30 thin, cylindrical, radial beams arising from its surface; numerous thin, conical spines also arise from its surface.
Measurements; based on 39 specimens from stations 27 and 71: diameter of cortical shell 87-144 µm [diameters >100 µm probably are of Cenosphaera sp from the Gulf of California], of outer medullary shell 37-46 µm, of inner medullary shell 15-20 µm.
| | Benson 1966 | Actinomma sol:
Three concentric shells. Outermost with regular, circular pores with well developed polygonal frames, usually bearing short bristle-shaped spines on the nodes (broken off in the specimen photographed); no primary (conspicuously larger) radial. Outermost shell diameter: 70-100 µm. | | Boltovskoy 1998 |
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