Aperture |
two rows of apertures in adult stage |
numerous apertural pores in the periphery |
a single row of eight-shaped foramina |
Size |
up to 15.000µm |
up to 10.000µm |
up to ?, smaller |
Test |
discoidal, biconcave |
discoidal, biconcave |
mainly discoidal, but following form of substrate, as permanently fixed from youth on |
Chamber arrangement |
proloculus followed by tubular enrolled second chamber |
ovate proloculus followed by cyclic chambers, without tubular enrolled second chamber |
proloculus followed by tubular enrolled second chamber of a nearly complete coil |
Images |
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Regional Distribution |
Indo-Pacific, not Caribbean |
mainly Pacific + Seychelles + Malidives, absent East coast of Africa |
circum-tropical including Mediterranean |