Bullinularia – Microworld

Bullinularia species, after Bobrov et al., 2020

Genus Bullinularia Deflandre, 1953

Diagnosis: Shell elliptical or circular in apertural view, hemispherical in lateral view with a flattened smooth ventral side; test yellow to dark brown, opaque, partly covered with mineral particles embedded in organic cement. Aperture is a long, eccentric, invaginated, curving slit, completely or partially hidden by the dorsal lip (cryptostome). The dorsal lip, and sometimes the ventral side, has some small or larger pores (key character!); nucleus vesicular.

Type species. Bullinularia indica (Penard, 1907)

Habitat. Soil, mosses.

B. gracilis

Key to the species of Bullinularia

1	Shell length exceeds shell breadth (mean l/b ratio is 1.13), ventral face is bellied, apertural furrow is very conspicuous	*B. foissneri*
–	Shell breadth exceeds shell length (l/b ratio less than 1.0), ventral face is flat, depressed	2
2	Shell breadth is more than 190 μm	*B. maxima*
–	Shell breadth is between 130 and 190 μm	*B. indica*
–	Shell breadth is less than 130 μm	3
3	Shell length/shell breadth ratio is 0.70–0.80; mean shell breadth is 120 μm; shell is chamois to brownish, transparent	*B. gracilis*
–	Shell length/shell breadth ratio is 0.85–0.95	4
4	Pores on the dorsal lip are small (2–3 μm) and numerous	*B. minor*
–	Pores on the dorsal lip are large (7–8 μm) and few	*B. macroporum*