Boreomysis Sars 1869, 330; Sars 1879, 8–10; Sars 1885, 177–178; Zimmer 1904, 429–430; Zimmer 1909, 52; Hansen 1910, 24; Banner 1948, 361–362; Tattersall O.S. 1955, 66–68; Ii 1964, 16–19.
The genus diagnosis is based on the descriptions provided by Sars (1869) and Ii (1964). Species of the genus Boreomysis have outer flagellum of antennule in both sexes swollen at the base and furnished with long sensory hairs. Male appendage on the antennule small. Antennal scale with its outer margin smooth and terminating in a spine, apex of the scale truncate, small oblique distal suture present. Labrum broader than long without frontal spine. Endopods of the third to eighth thoracic limbs with the sixth joint divided into 2–3 subjoints by distinct articulations. Pleopods of the male well-developed, biramous and natatory, endopods of the first pair rudimentary and unjointed, exopods of the second and third pairs more or less elongated, distal setae on the exopod of the third or both second and third pairs sometimes very short and reduced. The outer uropod with the proximal part of the outer margin with one or two spines. Transverse suture in the proximal part of the outer uropod present but difficult to observe. Females have seven marsupial lamellae.
To date, 39 species have been described (Anderson 2008). Only one species is recorded from New Zealand waters.