Cancricepon Giard & Bonnier, 1887

An, Jianmei, Wang, Mingxiao, Boyko, Christopher B. & Williams, Jason D., 2019, New hosts and localities for species of Cancricepon Giard & Bonnier, 1887 (Isopoda: Epicaridea: Bopyridae) with description of two new species and comments on the relationship between Cancricepon and Trapezicepon Bonnier, 1900, Zootaxa 4559 (1), pp. 136-150 : 148

Key to species of Cancricepon Giard & Bonnier, 1887 based on mature females

1. Mid-dorsal projections on pereomeres 1–7............................... C. multituberosum An, Yu & Williams, 2012

- Mid-dorsal projections on fewer than pereomeres 1–7......................................................... 2

2. Tergal projections on pereomeres 2–4 greatly enlarged........................................................ 3

- Tergal projections on pereomeres 2–4 small or lacking........................................................ 7

3. Large tergal projections strongly asymmetrical.................................................. C. castroi n. sp.

- Large tergal projections approximately symmetrical.......................................................... 4

4. Head strongly bilobed.......................... C. elegans Giard & Bonnier, 1887 or C. pilula Giard & Bonnier, 1887 1

- Head weakly bilobed or not bilobed....................................................................... 5

5. Head not bilobed................................................................ C. savignyi ( Stebbing, 1910)

- Head weakly bilobed................................................................................... 6

6. Tergal projections extremely swollen, medially indented and appearing distinct from median portion of their respective pere- omeres........................................................................ C. xanthi ( Richardson, 1910)

- Tergal projections contiguous with median of pereomeres, not medially indented................................................................................................ C. choprae (Nierstrasz & Brender à Brandis, 1925)

7. Tergal projections lacking....................................................... C. anagibbosus Bourdon, 1971

- Tergal projections on pereomeres 2–4, small................................................................ 8

8. Mid-dorsal projections on pereomeres 4–7, head not bilobed................................ C. garthi Danforth, 1970

- Mid-dorsal projections on pereomeres 5–7, head bilobed...................................................... 9

9. Head weakly bilobed, pereomeres 1 and 2 with median region distinct from lateral................... C. beibusinus n. sp.

- Head strongly bilobed, pereomeres entire............................................ C. knudseni ( Danforth, 1970)