Key to species of the genus Leiogalathea

1. Hepatic margin of carapace with 1 spine.................................................................. 2

- Hepatic margin of the carapace unarmed.................................................................. 8

2. Cornea clearly narrower than ocular peduncle..................................................... L. dido n. sp.

- Cornea as wide as ocular peduncle....................................................................... 3

3. Rostrum with 2 well developed lateral teeth proximally...................................................... 4

- Rostrum with lateral teeth rudimentary or minute (proximalmost may be distinct)................................... 7

4. Anterior branchial margin armed with 3 spines.................................................. L. turnus n. sp.

- Anterior branchial margin armed with 1 or 2 spines.......................................................... 5

5. P2–4 propodi stout, always less than 6 × as long as broad. Rostrum slender, more than 1.6–1.8 × as long as wide................................................................................................... L. aeneas n. sp.

- P2–4 propodi slender, 8–10 × as long as broad. Rostrum broad at base, 1.3–1.4 × as long as broad..................... 6

6. Flexor margin of P2 dactylus with 7 or 8 spines. P2 dactylus 0.5–0.6 × length of P2 propodus................................................................................................ L. agassizii (A. Milne Edwards, 1880)

- Flexor margin of P2 dactylus with 9 or 10 spines. P2 dactylus less than 0.5 × length of P2 propodus....... L. ascanius n. sp.

7. P1 densely covered with long setae. Rostrum about 1.2–1.3 × as long as broad........................ L. anchises n. sp.

- P1 not densely covered with long setae. Rostrum about 1.6 × as long as broad.......................... L. creusa n. sp.

8. Branchial margin of carapace with 0–2 spines............................................................... 9

- Branchial margin of carapace with 3 spines................................................................ 17

9. Margin of the rostrum strongly dentate, with 4 or 5 sharp teeth along nearly entire margin............... L. camilla n. sp.

- Margin of the rostrum smooth or with rudimentary teeth or at most with 2 or 3 well-developed proximal teeth........... 10

10. Rostrum slender, more than 1.6 × as long as wide, and length 0.4 × carapace length; usually downwards directed.................................................................................................. L. evander n. sp.

- Rostrum moderately slender, equal or less than 1.5 × as long as wide, and length 0.3 × carapace length; usually horizontal. 11

11. P2 propodus less than 6 × as long as broad................................................................. 12

- P2 propodus more than 6 × as long as broad................................................................ 14

12. Anterobranchial margin unarmed. Branchial dorsal surface with setae forming rows but usually without marked transverse ridges..................................................................................... L. paris n. sp.

- Anterobranchial margin with 1 spine. Branchial dorsal surface with marked setose transverse ridges................... 13

13. Sternite 3 moderately broad, 2.0–2.5 × as wide as long.............................................. L. priam n. sp.

- Sternite 3 broad, 3.3–4.0 × as wide as long...................................................... L. juturna n. sp.

14. Lateral margin of rostrum with minute teeth or at most with 2 or 3 well-developed proximal teeth..................... 15

- Lateral margin of rostrum smooth........................................................................ 16

15. Posterior branchial margin of carapace unarmed. Article 1 of antennule with distomesial spine... L. laevirostris (Balss, 1913)

- Posterior branchial margin of carapace often with 1 spine. Article 1 of antennule without distomesial spine... L. achates n. sp.

16. Posterior branchial margin with 1 spine....................................... L. imperialis (Miyake & Baba, 1967)

- Posterior branchial margin unarmed............................................................ L. amata n. sp.

17. Sternite 4 broadly contiguous to sternite 3. Distomesial spine of antennal article 1 not exceeding end of article 2..................................................................................................... L. sinon n. sp.

- Sternite 4 narrowly contiguous to sternite 3. Distomesial spine of antennal article 1 exceeding end of article 2. L. pallas n. sp.