(Leuckart, 1854)
Trunk elongate, up to 5.0 mm long (Oikopleura albicans). Buccal glands large. Gonads adjoining the coil of the gut as a semicircular clasp, and protruding dorsally when ripe, extending beyond the oral end. Tail musculature moderately broad. Subchordal cells numerous, small, and stellar, arranged in 2 lines over half of the tail length.