Cyproideidae

Ariyama, Hiroyuki, 2016, Five species of the family Cyproideidae (Crustacea: Amphipoda) from Japan, with the description of a new genus and two new species, Zootaxa 4097 (3), pp. 301-331 : 330

Key to species of the family Cyproideidae in Japan

1 Urosomite 1 not keeled, distal end of urosomites projected; anterodistal end of antenna 1 peduncular article 2 cuspidate; basis of pereonite 7 rectolinear............................................................................... 2

- Urosomite 1 keeled, distal end of urosomites not projected; anterodistal end of antenna 1 peduncular article 2 uncuspidate; basis of pereonite 7 expanded........................................................................... 4

2 Urosomites 2–3 coalesced, antenna 1 flagellum with 10–15 articles................. Metacyproidea makie gen. et sp. nov.

- Urosomites free, antenna 1 flagellum with 6–7 articles........................................................ 3

3 Eyes large (diameter longer than half of head), coxa 5 far exceeding posteroventral corner of pereonite 6; body with dark brown bands........................................................................ Cyproidea liodactyla

- Eyes small (diameter shorter than half of head), coxa 5 barely reaching posteroventral corner of pereonite 6; body color whitish........................................................................... Cyproidea okinawensis sp. nov.

4 Posterior margin of urosomite keel rounded, basis of pereopod 6 expanded................ Moolapheonoides acutifalcatus

- Posterior margin of urosomite keel pointed, basis of pereopod 6 rectolinear.................. Terepeltopes dolichorhunia