Zibrowius (1973) found the Mörch specimen in the British Museum and wrote " The types of Morch's var. articulata have been rediscovered recently (BMNH. 1965. 31. 14-16). These tubes are similar to other serpulids such as Spirobranchus, Pomatoceros, Pomatoleios, and Galeolaria. A preserved operculum was extracted from one of these tubes; it is a massive calcareous operculum similar to that of Pomatoleios kraussii (Baird)." Thus he did not synonymise 'articulata' under 'kraussii', only noted the opercula were 'similar'. Even if they were synonyms this would not be possible as 'articulata' is one year senior to 'kraussii'
Zibrowius, Helmut. (1973). Revision of some Serpulidae (Annelida Polychaeta) from abyssal depths in the Atlantic and Pacific, collected by the 'Challenger' and Prince of Monaco Expeditions. <em>Bulletin of the British Museum (Natural History).</em> 24 (9): 427-439.available online athttps://biodiversitylibrary.org/page/26497963 Available for editors [request]