Genus Orbignyella Ulrich & Bassler, 1904

TYPE SPECIES. — Orbignyella sublamellosa Ulrich & Bassler, 1904 by original designation. Middle Ordovician; United States.

DIAGNOSIS. — Colonies encrusting, massive or globular. Prismatic autozooecia with polygonal apertures. Autozooecial diaphragms abundant, straight or inclined, often cystoid. Exilazooecia rare, short, with or without diaphragms. Acanthostyles small or large, varying in number. Autozooecial walls thin or weakly irregularly thickened, with indistinct laminated microstructure, often serrated.

OCCURRENCE. — Ordovician – Silurian; worldwide.

COMPARISON

Orbignyella Ulrich & Bassler, 1904 differs from Cyphotrypa Ulrich & Bassler, 1904 in having of abundant and inclined diaphragms.