Key to males of species of Antomicron Cobb, 1920

1. Males with both alveolar and tubular supplements............................................................ 2

- Males with only tubular supplements..................................................................... 6

2. Number of alveolar supplements is more than 25 (29–36)..................................................... 3

- Number of alveolar supplements is less than 20 (8–14)....................................................... 4

3. Males with 5–9 tubular supplements........................................................... A. intermedius

- Males with 3 tubular supplements............................................................... A. alveolatum

4. Males with 5 tubular supplements............................................................... A. profundum

- Males with 2–3 tubular supplements...................................................................... 5

5. Males with 3 tubular supplements; cephalic sensilla papilliform......................................... A. pratense

- Males with 2 tubular supplements; cephalic sensilla setiform..................................... A. lorenzeni sp. n.

6. Males with 15 tubular supplements; body length exceeds 1.3 mm ......................... A. quindecimpapillatus sp. n.

- Number of tubular supplements is 10 or less; body length is less than 1.1 mm ..................................... 7

7. Males with 10 tubular supplements; amphid loop-shaped............................................ A. profundum

- Males with 4–8 tubular supplements; amphid doughnut-shaped................................................ 8

8. Males with 6–8 tubular supplements, amphid oval in shape........................................... A. pellucidum

- Males with 4 tubular supplements, amphid elongate in shape........................................... A. elegans