Domicola lithodesi, a new genus and species of gammaridean amphipod is described. It is placed in the family Calliopiidae. Two specimens, a male and a preparatory female, were collected in August 1990 from the pleonal cavity of the lithodid crab Lithodes ferox (Filhol, 1885), an anomuran crab caught at 300 m depth from off Namibia. The more relevant characters are: anophtalmous; body smooth, gammarid-like, male smaller than female, urosomite 1 with a prepeduncular spine; telson broad, entire, unlobed and unarmed; short rostrum; accessory flagellum scale-like, calceoli absent; lower lip without inner lobes; coxa 4 posteriorly excavated; gnathopods basic, subequal, with numerous palmar spines; dactyls on P3-7 with specialized adhesive organs; coxal gill 7 present; uropods eusirid type.