Two new species of Pogonophora from the arctic mud volcano off northwestern Norway

Collections of Pogonophora made by the research vessels Hakon Mosby and Professor Logachev in the Norwegian Sea in 1995-1996 contain two new species belonging to the genera Sclerolinum and Oligobrachia. Both species were obtained on the continental slope northwest of Norway in the area of an anomalous cold seep of a mud volcano type. Sclerolinum contortum sp. nov. differs from the congeneric species in having a rather long opisthosome with very few segments (4-5) and tubes open at both ends and strongly folded upon themselves to show regular S-bends. Oligobrachia haakonmosbiensis sp. nov. is well distinguished by a set of features, especially by the lack of glandular patches on the first two segments, that is very unusual for Oligobrachia. A detailed comparison of all species of the single genus in the subclass Monilifera, Sclerolinum, is given.