Nephasoma diaphanes (Gerould)

Phascolosoma diaphanes Gerould, 1913:395 .

Type locality: Off eastern seaboard of the U.S., Cape Cod to New Jersey, 90–2400 m.

Remarks: These 99 worms are commonly 2–10 mm long with a few large ones in the 15–20 mm range, and one 25 mm giant. They are slender, transparent, have small pale scattered hooks, and reduced lobe­like tentacles. The papillae are usually inconspicuous, but in some individuals those towards the posterior end may be quite distinct and dark reddish­brown. It is not uncommon to find this species living inside arenaceous foraminiferan tests or vacated polychaete tubes. A parasitic nematode was living within the body cavity of a worm from Stn S201.

Distribution: Cosmopolitan from 82° N to 78° S in cold water, mostly from bathyal and abyssal depths, down to 5300 m. Edmonds (1976) reported the species from off New Zealand in 600–660 m at 46° S, 171° E. These records strengthen the assertion that this is a truly cosmopolitan cold­water species.