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General morphology of Lacogromia cassipara. ah – hyaline peduncular sheath; p – peduncle; e – internal channel; g – granuloreticulopodia; n – nucleus; m – membrane; x – xenosomes; c – cap of adhering bunch of xenosomes.

Class Monothalamea Pawlowski et al. 2013

Diagnosis: Foraminifera with a single chamber (monothalamous) test with an organic or agglutinated wall.

Remarks: Monothalamid foraminifera are widely distributed in marine and brackish habitats. Some members of this class are found in freshwater, but are rare. The main reason is probably that light microscopically, these tests are difficult to detect between debris, despite their relatively large size (250 µm on average, but up to 1 mm). Usually, the amoebae extend their pseudopodial network up to several mm when kept in Petri dishes or in wet mounts in moist chambers. Then they can be easily detected with an inverted microscope, preferably with dark field illumination or phase contrast.

The following non-marine families are known both morphologically and genetically:

Lieberkuehniidae: Lieberkuehnia, Claparedellus
Edaphoallogromiidae: Edaphoallogromia
Velamentofexidae: Velamentofex
Lacogromiidae: Lacogromia
Limnogromiidae: Limnogromia
Reticulomyxidae: Reticulomyxa, Haplomyxa, Dracomyxa, Wobo

Lacogromia cassipara, morphotype B; a adult specimen; b young specimens, just 24 hours after schizogony – drawing and micrograph Ferry Siemensma (1982)
Lacogromia cassipara, four young specimens, just 24 hours after schizogony (Siemensma, 1982)
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