Description of Psammina

Test fragile, brittle, basically plate-like andtypically discoidal but sometimes folded into more complex shapes. Circular apertures developed along margin in some species. External xenophyae firmly cemented to form upper and lower plates; internal xenophyae sparse, commonly forming pillar or bar-like structures between plates. Granellare branches and well-developed stercomare strings run between plates and branch around pillars. Occurrence: Northeast Atlantic, equatorial and west Pacific, 1158-6059m. Type species Psammina nummulina Haeckel, 1889.