Key to known females of species of Antomicron Cobb, 1920

1. Amphid loop-shaped; body shorter than 0.7 mm ............................................... A. lorenzeni sp. n.

- Amphid doughnut-shaped; body longer than 0.7 mm ......................................................... 2

2. Central amphidial elevation oval, amphid rounded.......................................................... 3

- Central amphidial elevation elongate; amphid elongate....................................................... 4

3. Body shorter than 1 mm; cephalic setae 2–3 µm long.............................................. A. intermedius

- Body longer than 1 mm; cephalic setae 6 µm long.................................................. A. pellucidum

4. Body shorter than 1.1 mm; plumper (a = 26–36) and with shorter tail (c' = 6.4)............................. A. elegans

- Body longer than 1.3 mm; slenderer (a = 50) and with longer tail (c' = 8.4)................. A. quindecimpapillatus sp. n.