*Data for the northwest Atlantic come from anchor dredge samples on the Gay Head–Bermuda transect (Sanders
et al. 1965). The column for <4000 m averages 10 stations, ranging in depth from 200 m to 2870 m. Seven stations
having a depth range of 4436–5001 m were used for the second column.
(^) **The North Central Pacific data are averages of 10 0.25 m^2 cores, all from the same spot at 28°30′N, 155°20′W
at 5497–5825 m depth.
(^) Jumars (1975) studied a large suite of box cores from abyssal depths in the central
Pacific. As is typical, polychaetes were about half the fauna by numbers and bulk.
The four most abundant species made up half of the individuals. They were
Chaetozone sp. (18.5%), Capitella sp. (15.8%), Flabelligella sp. (11.4%) and Tharyx
sp. (6%). The first and fourth both come from the family Cirratulidae (Fig. 13.7a),
which in shallow water are deposit-feeders living within the sediment, perhaps sorting
sediment before ingestion or testing sediment richness with tentacles on the