(Fig. 4A–D)
Gennadas borealis Rathbun, 1902a: 24; 1904: 147, figs. 88–89. — Schmitt 1921: 24, fig. 11. — Kobyakova 1937: 141, fig. 9. — Goodwin 1952: 393. — Kozloff 1974: 162.
Bentheogennema borealis. — Anderson & Lindner 1943: 295. — Pearcy & Forss 1966: 1137. — Butler 1980: 41. — Krygier & Pearcy 1981: 77. — Hendrickx & Estrada-Navarrete 1989: 106; 1996: 13, fig. 3 (extensive synonymy) — Pérez Farfante & Kensley 1997: 58. — Wicksten 2002: 129.
Diagnosis. Exoskeleton membranous, smooth. Rostrum short, with dorsal tooth, acute apex, extending posteriorly as mid-dorsal carina. Carapace with suborbital tooth rounded, low antennal tooth, branchiostegal tooth strong, extending posteriorly into carina, pterygostomian margin rounded, cervical, postcervical grooves widely separated on dorsal midline; antennal, branchial carinae extending posteriorly, meeting hepatic carina. Eye pigmented, with tubercle on eyestalk. Stylocerite short, with wide base. Scaphocerite rounded, scale exceeding lateral tooth. Kink in flagellum of antenna. Second maxilliped flattened, setose. Third maxilliped longer than second, flattened, setose; dactyl flat, twisted; with exopod, podobranch. Pereopods 1–3 chelate, sturdy, with epipods, podobranchs. Pereopods 4, 5 slender, with simple dactyls. Abdominal somites with small grooves, pleura blunt to rounded. Somite 6 with dorsal carina. Telson shorter than uropods, narrow, truncate, with 2 pairs movable spines, dorsal groove. Total length 58–64 mm.
Color in life. Red.
Habitat and depth. Pelagic, 100–2560 m, maximum density at 600–1000 m.
Range. Japan and Bering Sea to Coronado Is., Baja California. Type locality Medny I., off Copper I.; Kamchatka.