Bullinularia gracilis Thomas, 1959

Diagnosis: Test ellipsoid, chitinoid, with a thin covering of xenosomes, but sometimes without any xenosomes; pores and pseudostome as with B. indica, but much smaller. Color from bright yellow to brown, test transparent.

Dimensions: Thomas (1959): about 120 µm. My measurements: 160-164 µm.

Ecology: soil, mosses.

Remarks: (From Lueftenegger and Foissner:) Hoogenraad & De Groot (19526) describe two shell types for B. indica. The ‘extraordinary’ type is firm and inflexible, the ‘normal’ type is flexible and rather tenacious, consisting of a homogenous matrix, as stated also by Penard (1912). We suggest that the outer organic layer, which seems to be somewhat elastic, is responsible for the above mentioned flexibility of shells in some Bullinularia populations.