Planhoogenraadia gracilis Bonnet & Gomez-Sanchez 1984

Diagnosis: Shell yellowish or brownish, with simple cryptostome. In dorsal view, the test often has an asymmetrical shape as a result of a slight twist compared to the great axis of the test. The apertural end is rounded, the fundus tapers towards a sometimes relatively acute point. In some individuals, there is a slight constriction between visor and belly. In cross-section the test is elliptical. In side view, the ventral region is more or less curved. There is a light dorsal projection at the edge of the visor and the belly. The invagination between belly and visor is deep (1/6 to 1/3 of the height). The maximum height is in the middle of the test. Th visor is well differentiated, rather strongly overlapping the aperture. In ventral view the aperture is crescent-shaped, usually hidden by the visor. There are small teeth on the dorsal lip. Shell covered with irregular siliceous plates.

Dimensions: Length 63—70 µm; width 34—43 µm; aperture 20—25 µm; invagination between visor and belly 9.2—12.3 µm.

Ecology: Brown forest soils.

Geographical distribution: Spain (Asturias).

Remarks: The convexity of the ventral side resembles the genus Hoogenraadia, but the apertural region is of the Planhoogenraadia type.

References: Bonnet, L., Gomez-Sanchez, M. (1984) Note préliminaire sur le peuplement thécamoebien des sols des Asturies (Espagne). Bull. Soc. Nat., 120: 111-116