Since 1993 Cerithiella danielsseni (Friele, 1877) has been regarded as a variety of C. metula (Lovén, 1846). An argument is made for reinstating C. danielsseni as a valid taxon inhabiting below-zero waters on the slope around the Nordic Seas. This conclusion is based on lack of overlap in shell morphology between specimens found below and above the ecotone where the thermocline meets the slope. Just above the ecotone and also in the Barents Sea north of ~72°N, the shelf species C. metula occurs, but with morphology slightly modified from that of the ‘typical’ form.
