Key to Australian species of Uroptychus

1 Rostrum about as broad as long ................................................................................... 2

— Rostrum distinctly longer than broad............................................................................ 3

2 Anterior emargination of sternite 3 without pair of median spines. Basal antennal segment without small outer distal spine.................................................. U. yokoyai n. sp.

— Anterior emargination of sternite 3 with pair of median spines. Basal antennal segment with small outer distal spine ............................................................... U. alcocki n. sp.

3 Lateral margins of carapace smooth or crenulate.......................................................... 4

— Lateral margins of carapace dentate or with distinct spines........................................ 15

4 Carapace distinctly broader than long (excluding rostrum) .......................................... 5

— Carapace length (excluding rostrum) as long as or longer than broad........................ 10

5 Dactyli of walking legs with 2 distal spines............................... U. pilosus Baba, 1981

— Dactyli of walking legs with more than 8 spines or denticles along flexor margin ..... 6

6 Ultimate and penultimate segments of antennal peduncle each with distal spine ........ 7

— Ultimate and penultimate segments of antennal peduncle without distal spine............ 8

7 Basal antennal segment with outer spine ................................................ U. latus n. sp.

— Basal antennal segment without outer spine ................................ U. laperousazi n. sp.

8 Antennal scale overreaching apex of distal peduncle segment. Basal antennal segment with small outer spine. Outer orbital angle acute................................... U. babai n. sp.

— Antennal scale reaching to about midlength of distal peduncle segment. Basal antennal segment without outer spine. Outer orbital angle rounded ........................................... 9

9 Cheliped about 3 times carapace length; dorsal margin of propodal palm about 2.5 times as long as dactylus. Teeth lining flexor margin dactyli of the walking legs slender and longer than wide ..................................................................... U. longvae n.sp.

— Cheliped about 2 times carapace length; dorsal margin of propodal palm about 2.5 times as long as dactylus. Teeth lining flexor margin dactyli of the walking legs short, about as longer as wide ........................................................................ U. patulus n.sp.

10 Dactyli of walking legs with 2 distal spines.................................................................... ............................................................ U. thermalis Baba & de Saint Laurent, 1992

— Dactyli of walking legs with 7 or more spines along flexor margin ........................... 11

11 Spines lining flexor margin of dactyli oriented parallel to margin ................................. .................................................................................... U. australis (Henderson, 1885)

— Spines lining flexor margin of dactyli oriented oblique to margin ............................. 12

12 Cheliped robust, about 3 times carapace length. Carapace margins divergent, widest at about posterior fifth ............................................................................ U. litosus n. sp.

— Cheliped slender, about 3.5–4.0 times carapace length. Carapace margins subparallel or slightly divergent, widest at about posterior quarter............................................... 13

13 Merus of third walking leg about half­length of merus of second walking leg. Sternite 4 with field of granules ................................................................... U. empheres n. sp.

— Merus of third walking leg about two­thirds length or greater than merus of second walking leg. Sternite 4 smooth or with transverse row of granules ............................ 14

14 Penultimate segment of antennal peduncle unarmed. Merus of third walking leg longer than two­thirds length of second walking leg ..... U. gracilimanus (Henderson, 1885)

— Penultimate segment of antennal peduncle with distal spine. Merus of third walking leg about nine­tenths length of second walking leg .................... U. brucei Baba, 1986

15 Lateral margin of carapace with single strong above base of first walking leg .............. ............................................................................................... U. raymondi Baba, 2000

— Lateral margin of carapace with more than 1 lateral spine or tooth............................ 16

16 First walking leg markedly more slender than second walking leg ...... U. nowra n. sp.

— First walking leg similar to second walking leg.......................................................... 17

17 Penultimate segment of antennal peduncle unarmed distally; length about one­quarter that of ultimate segment .................................................................... U. flindersi n. sp.

— Penultimate segment of antennal peduncle with distal spine; length half or greater than that of ultimate segment .............................................................................................. 18

18 Antennal scale reaching about to midlength of ultimate peduncle segment. Ultimate antennal peduncle segment unarmed distally.............................................................. 19

— Antennal scale almost reaching or exceeding apex of ultimate peduncle segment. Ultimate antennal peduncle segments with distal spine ................................................... 20

19 Carapace with dorsal spines on anterior region; lateral margins with 7 or more strong spines .................................................................................................... U. calcar n. sp.

— Carapace without dorsal spines; lateral margins with 4 or 5 small spines...................... ....................................................................................................... U. longicheles n. sp.

20 Lateral margins of carapace denticulate or with small spines..................................... 21

— Lateral margins of carapace with strong spines .......................................................... 23

21 Rostrum distally trifid, dorsally excavated. Anterolateral spines of carapace not overreaching outer orbital spine or angle........................................ U. multispinosus n. sp.

— Rostrum neither distally trifid nor dorsally excavated. Anterolateral spines of carapace overreaching outer orbital spine or angle.................................................................... 22

22 Outer orbital angle rounded. Carapace dorsum setose .................... U. hesperius n. sp.

— Outer orbital angle spiniform. Carapace dorsum naked................ U. subsolanus n. sp.

23 Carapace with epigastric spines .................................................................................. 24

— Carapace without epigastric spines ............................................................................. 25

24 Dactylus of walking legs with 8–10 strong spines on flexor margin. Dorsum of carapace smooth (except for epigastric spines) ......................................... U. zeidleri n. sp.

— Dactylus of walking legs with 16–20 small spines on flexor margin. Dorsum of carapace rugose, setose ............................................................................... U. cardus n. sp.

25 Carapace with 4 lateral spines (excluding anterolateral spine). Propodi of walking legs with single distal spine on flexor margin ................................................ U. belos n. sp.

— Carapace with 6–10 lateral spines (excluding anterolateral spine). Propodi of walking legs with row of spines on flexor margin.................................... U. paracrassior n. sp.