Diagnosis.—Asty incrusting, uniserial, with bilateral and unilateral branching; œcia dimorphic; normal œcia with short caudæ or without caudæ pyriform; termen a complete, high, narrow, oval ridge with few small spines on its circumference and, at the proximal-lateral corners of the aperture, a pair of stout spines which sometimes, if not always, bend towards one another and fuse in the middle line; apparently there are no spines around the distal end of the aperture; extra-terminal front-wall well-developed proximally, and arched; intra-terminal front-wall a wide, depressed lamina; aperture oval, sub-quadrate, somewhat constricted laterally; avicularia small, one, or a pair, placed laterally and somewhat distally with regard to each aperture, rather abruptly pointed with the distal ends curved towards the aperture they encompass; ovicells hyperstomial.