Vosseler, 1901
Length to 9 mm. In females (Phronima stebbingi 1), pleon and urosoma (including UR) combined 1.17±0.08 times as long as head and pleon combined; pleonite I 1.15±0.05 times as long as pereonite VII (unique character). P V similar to that of Phronima atlantica, ART 5 longer than wide (Phronima stebbingi 3). Exopodite of UR II much longer than endopodite.
In males (Phronima stebbingi 2), pleon and urosoma (including UR) combined 1.27±0.06 times as long as head and pleon combined; pleonite I 1.25±0.08 times as long as pereonite VII (unique character). P V similar to that of female but ART 5 as wide as long. Exopodite of UR II much longer than endopodite.