[Introduction:]
In all 43 species of polychaetous Annelids have been brought home by the Danmark Expedition. Of these the great majority consist of the ordinary arctic, coastal forms and give the well-known picture of the fauna, which is characterized chiefly by such species as
Harmothoe imbricata and
nodosa,
Nychia cirrosa,
Flabelligera affinis,
Pectinaria hyperborea,
Thelepus circinnatus etc. — Further, from a few localities in deeper water the Danmark has brought home on the one hand some less known and rarer forms, e. g.
Harmothoe multisetosa Moore and
Trophonia hirsuta G. Ar. Hansen, on the other hand a single new species of the genus
Harmothoe.
Among the commoner forms interest is attached to the species
Nereis zonata, which occurs in large numbers, some of the individuals in the epitokous form, and also to
Scalibregma inflatum, of which the variety
corethrura set up by MICHAELSEN is present in quantities. It appears on examination, as also from some notes by the zoologist of the Expedition in the Journal of the Danmark, that the form in question is not a variety, but must be the hitherto unknown, epitokous form of
Scalibregma inflatum.
