World Polychaeta Database (WPolyDb)
vol printed 1884 for year 1883, no article dates seen
Note that the BHL digitisation is a separate from the journal with two paginations running. The true paginations matching the journal are the set near the spine.
Ton van Haaren: On page 325 he ends his paper with Kopenhagen, in May 1884; also on BHL as: https://www.biodiversitylibrary.org/page/60030515 with pages 92-350