Betapista dekkerae, new genus and new species, is described. The generic diagnoses for
Laphania and
Scionides are improved after inspection of the holotypes of the type species.
Eupolymnia heterobranchia (syn.,
E. crescentis) is redescribed. Additions to the descriptions, based on study of type material, are made for
Laphania boecki (new record, Northeast Pacific),
Neoamphitrite robusta (syn.,
Scionides dux),
Neoleprea californica and
N. spiralis,
Pista brevibranchiata (new record, British Columbia [B.C.], Washington [WA], Japan) and
P. fratrella, and
Polycirrus californicus (new record, B.C., WA, syn.,
P. perplexus). Other additions to the descriptions are provided for
Amaeana occidentalis (new record, B.C.) and
Pista cristata. Two further
Pista species (one from the Skagerrak) and five
Polycirrus species are characterized but not named. Other new records are
Lanassa venusta venusta (B.C.),
Lysilla loveni, and
Neoleprea japonica (the two latter for Northeast Pacific).
Lysilla pacifica,
Pista fasciata, and
P. fratrella are shown not to be members of the fauna of British Columbia and Washington. Presumably, neither is
Polycirrus caliendrum. New observations on the types of the Antarctic
Polycirrus kerguelensis and
Ereutho kerguelensis are noted.
