1. Pereopod 5; longer teeth on anterior margin of carpus nearly as long as width of carpus....................................................................................................................................... 2
Pereopod 5; length of longer teeth on anterior margin of carpus about 0.3–0.5 x width of carpus........................................................................................................................ 5
2. Pereopod 5; row of teeth on anterior margin of carpus with short tooth proximally.... 3
Pereopod 5; row of teeth on anterior margin of carpus with one of the longer teeth proximally.................................................................................................................... 4
3. Distribution restricted to southern hemisphere; subantarctic province. Rostrum conforming to contour of head, about 0.4x width of head ................................................................................................................................... P. macropa GuérinMéneville, 1836
Distribution restricted to North Pacific; subarctic province. Rostrum truncate, limited to space between first antennae P. abyssalis (Bowman, 1968)
4. Pereopod 7; basis length about 1.2 x length of remaining articles combined................. .............................................................................................. P. johnsoni Bowman, 1978
Pereopod 7; basis length more than 1.5x length of remaining articles combined.......... .............................................................................................. P. latreillei Stebbing, 1888
5. Pereopod 5; length of longer teeth on anterior margin on carpus about 0.3x width of carpus. Pleon subequal in length to pereon ........................ P. brevidens Bowman, 1978
Pereopod 5; length of longer teeth on anterior margin of carpus about 0.5x width of carpus. Pleon length about 1.4x length of pereon .................... P. evansi Sheader, 1986