Porroecia, Martens, 1979

Chavtur, Vladimir G. & Bashmanov, Alexander G., 2018, Pelagic ostracods of the new subtribe Conchoeciina (Ostracoda, Crustacea) from the North Pacific, Zootaxa 4516 (1), pp. 1-127 : 74-75

Key for species of genus Porroecia

Adult males:

1. Capitulum of the frontal organ is has a pointed tip; ventral margin of the basale of the sixth limb is with two short and bare setae...................................................................... P. acutirostrata Chavtur , sp. nov.

- Capitulum of the frontal organ has a rounded tip; ventral margin of basale of the sixth limb is with one or three short and bare setae............................................................................................... 2.

2. Surface of the carapace is with conspicuous concentric striations; seta-a reaches the proximal margin of the first segment on the first antenna; masticatory pad has only three flaps and about 10–12 seta-like filaments.......... P. vibekensis (Poulsen) .

- Surface of the carapace is smooth or with only obscure sculpturing consisting of either weak striations oriented dorso-anteriorly or rarely weak concentric striations; seta-a only reaches or barely extends beyond the boundary between the first and the second segments of the first antenna; masticatory pad has four flaps and about 20–30 seta-like filaments............... 3.

3. Length of the carapace is 0.9–1.2 mm (up to 1.3 mm in Poulsen 1973); armature of seta-e on the first antenna has 8–10 distal pairs of “т”-shaped spines and 14–20 proximal alternated spines, ending in single row.............. P. spinirostris (Claus) .

- Length of the carapace is more than 1.2 mm; armature of seta-e on the first antenna has 11–16 (exception: 8–10 for P. porrecta in Drapun & Smith 2012 ) distal pairs of “σ”-shaped spines and 20–30 proximal alternating spines..................... 4.

4. Carapace has weak concentric sculpture; ventral margin of the basale of the sixth limb has a short and bare seta............................................................................................ P. affinis Chavtur , sp. nov.

- Carapace has weak dorso-anterior striations (conspicuous striations only in P. cf. porrecta —our material); ventral margin of the basale of the sixth limb has three short and bare seta........................................ P. porrecta (Claus)