Genus Erenna Bedot, 1904

Diagnosis. Nectophores flattened in the upper/lower direction, with tapering axial wings; distinct upper and lower lateral ridges respectively form upper and lower margins of lateral surface, with short, perpendicular, vertical lateral ridge connecting them. Lateral radial canals straight, with or without additional small protuberances, spikes, or 'horn' canals. Bracts of two types, with bracteal canal ending distally below a cupulate process containing ectodermal cells, including nematocysts. Tentillum large, with hypertrophied, uncoiled cnidoband and, when present, rigid terminal process devoid of nematocysts. Gastrozooid with large swollen basigaster, but no obvious peduncle.