Metacyproidea

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 : 314

Genus Metacyproidea , new

[Japanese name: Kawari-hoteiyokoebi-zoku, new]

Type species. Metacyproidea makie sp. nov. by monotypy.

Diagnosis. Most of morphological characters share with Cyproidea . Different characters from Cyproidea are as follows. Urosomites not keeled, urosomites 2–3 coalesced, posterodorsal end of coalesced urosomites strongly projected. Antenna 1 stout, peduncular article 2 dorsally crested, distal end distinctly toothed; accessory flagellum vestigial; flagellum short, with 10–16 articles. Upper lip incised, asymmetrical, with large roundish appendix. Mandible, incisor and accessory blades developed, molar reduced; palp slender, with 3 articles. Lower lip, inner lobes present. Maxilla 1, inner plate medium-sized; outer plate with 7 distal robust setae; palp 1-articulated, with 6 robust setae apically, mediodistal margin serrated. Coxa 6 wide. Telson reaching three fourths of uropod 3 peduncle, distal end truncate.

Etymology. From the Greek meta (= beyond) and Cyproidea (related genus).

Remarks. Metacyproidea gen. nov. closely resembles Cyproidea , especially in the peduncular article 2 of antenna 1 with a distinct distal tooth and the posterodorsal end of urosomites with a strong projection. However, Metacyproidea can be distinguished from Cyproidea by the coalesced urosomites 2–3 and the antenna 1 with a 10– 16-articulated flagellum. Detail structure of the mouth parts and width of the coxa 6 are also different. In addition, Paracyproidea Stebbing, 1899 has such a tooth of the antenna 1 ( Moore 1992), but its telson is fleshy ( Cyproidea and Metacyproidea have a flattened telson).

Included taxa. Metacyproidea makie sp. nov.