1a. LAG opens>20%CL posterior to tip of rostrum............................................................. 2

1b. LAG opens <20%CL posterior to tip of rostrum............................................................. 5

2a. LAG opens>30%CL posterior to tip of rostrum................................................ Juryoecia n.gen.

2b. LAG opens 20–30%CL posterior to tip of rostrum............................................................ 3

3a. RAG opens <5%CL behind the posterior end of the hinge between the carapace valves; a-seta on the A1 simple without any supplementary basal filament.............................................................. Deeveyoecia n.gen

3b. RAG opens>5%CL behind to the posterior end of the hinge; a-seta on A1 may have one or two supplementary filaments.. 4

4a. a-seta on A1 carries two supplementary basal filaments; the posterior margin of the carapace curves smoothly so RAG does not open at an apex, there is a faint sculpturing of longitudinal lines on the flanks of the carapace........... Vityazoecia n.gen.

4b. a-seta on A1 without supplementary basal filaments, posterior margin is clearly angled, with RAG opening at the apex, there is no sculpturing on the carapace............................................................ Muelleroecia n.gen.

5a. LAG opens in front of the anterior end of the hinge between the valves of the carapace (i.e. on the rostrum).. Nasoecia n.gen.

5b. LAG opens behind the anterior end of the hinge............................................................ 6

6a. RAG clearly opens at the apex of an angle in the posterior margin below the PDC.................................. 7

6b. RAG opens very close to the PDC. (often hard to see without mounting the carapace on a slide). The posterior margin curves smoothly............................................................................................8

7a. Armature on the e-seta of A1 consists of a single row of flanged spines............................ Austrinoecia n.gen.

7b. Armature on the e-seta of A1 consists of a double row of spines, which are paired distally and alternate proximally.............................................................................................. Clausoecia n.gen.

8a. Armature on the e-seta of A1 consists of a double row of slim, pointed spines lying parallel to the seta pointing basally and are either paired and/or partially alternating....................................................................9

8b. Armature on the e-seta of A1 consists of a double row of square-ended, keeled, alternating spines insert at right angles to the seta.................................................................................... Kyrtoecia n.gen.

9a. Small globose species (<0.9 mm); hook appendages on the A2 endopodites are similar and strongly curved; copulatory appendage distally swollen and has a large stylet.............................................. Rotundoecia n.gen.

9b. Small to medium-sized, non-globose species; hook appendage on left A2 endopodite markedly large than on the right, and is only moderately curved; copulatory appendage is straight sided and has a small stylet................... Metaconchoecia