Porcellanidae

Key to Indo-West Pacific genera of the Porcellanidae View in CoL

1. Antennal peduncle with movable (second to fourth) articles freely accessible to orbit .............................. 2

- Antennal peduncle with movable articles excluded from orbit by projection of immovable (first) article meeting anterior margin of carapace ........................................................................................................... 6

2. Chelipeds flattened. Pterygostomian flap entire .......................................................................................... 3

- Chelipeds robust. Posterior part of pterygostomian flap composed of 1 or more pieces separated by mem- branous interspaces from anterior part............................................................ Pachycheles Stimpson, 1858 View in CoL

3. Rostrum narrow, triangular, with row of spines on each lateral margin. Telson composed of 5 plates ........................................................................................................................................ Petrocheles Miers, 1876 View in CoL

- Rostrum broad, unarmed except for sometimes with supraocular spine on each lateral margin. Telson composed of 7 plates ................................................................................................................................... 4

4. Carapace with gastric region strongly elevated. Ambulatory legs subcylindrical.............................................................................................................................................................. Neopetrolisthes Miyake, 1937a View in CoL

- Carapace flattish or somewhat convex on dorsal surface. Ambulatory legs flattish ................................... 5

5. Carapace uneven on dorsal surface. Median lobe of rostrum with pair of lateral elevations................................................................................................................................................... Novorostrum Osawa, 1998a View in CoL

- Carapace genarally even on dorsal surface. Median lobe of rostrum without lateral elevations ............................................................................................................................................ Petrolisthes Stimpson, 1858 View in CoL

6. Carapace broader than long ......................................................................................................................... 7

- Carapace as long as or longer than broad .................................................................................................. 11

7. Ambulatory legs with dactyli each terminating in simple claw (no corneous spines present on flexor mar- gin).................................................................................................................... Raphidopus Stimpson, 1858

- Ambulatory legs with dactyli each with biunguiculate claw....................................................................... 8

8. Branchial margins of carapace armed with spines, outer orbital angle terminating in small spine.................................................................................................................. Aliaporcellana View in CoL Nakasone & Miyake, 1969

- Branchial margins of carapace without spines, outer orbital angle unarmed .............................................. 9

9. Carapace with pair of transverse ridges along cervical regions. Telson composed of 5 plates ............................................................................................................................................. Heteropolyonyx Osawa, 2001 View in CoL

- Carapace with weak or distinct, cervical grooves. Telson composed of 7 plates ...................................... 10

10. Carapace with dorsal regions well defined by grooves; cervical and gastric grooves formed by thinning and gradual decalcification of cuticle........................................................Eulenaios Ng & Nakasone, 1993

- Carapace with dorsal regions not distinctly defined by grooves.......................... Polyonyx Stimpson, 1858 View in CoL

11. Carapace distinctly elongate. Dactyli of ambulatory legs triunguiculate or quadriunguiculate................ 12

- Carapace not elongate. Dactyli of ambulatory legs each terminating in a single claw ............................. 13

12. Carpi of chelipeds longer than broad. Dactyli of ambulatory legs quadriunguiculate ............................................................................................................................................................... Porcellanella White, 1852 View in CoL

- Carpi of chelipeds broader than long. Dactyli of ambulatory legs triunguiculate............................................................................................................................................. Pseudoporcellanella Sankarankutty, 1961

13. Carapace strongly areolate on dorsal surface ............................................................................................ 14

- Carapace nearly smooth or striate on dorsal surface ................................................................................. 15

14. Branchial margins of carapace with spines. Chelae flattened ........................... Enosteoides Johnson, 1970 View in CoL

- Branchial margins of carapace without spines. Chelae inflated..................... Capilliporcellana Haig, 1978 View in CoL

15. Chelipeds subequal, dactyulus of smaller cheliped not twisted.......................... Porcellana Lamarck, 1801 View in CoL

- Chelipeds unequal, dactylus of smaller cheliped usually twisted.............................................................. 16

16. Carapace with dorsal regions clearly defined. Rostrum broadly triangular or rounded in dorsal view, median lobe strongly deflexed............................................................................... Ancylocheles Haig, 1978

- Carapace with dorsal regions weakly defined. Rostrum horizontal, tridentate or trilobate in dorsal view [except for Pisidia dispar ( Stimpson, 1858) with rostrum strongly bent ventrally, broadly rounded in dor- sal view]..................................................................................................................................................... 17

17. Chelae rather flattish, showing pronounced sexual dimorphism in spinulation as well as in degree of dis- tortion of fingers............................................................................................................ Pisidia Leach, 1820

- Chelae subcylindrical, generally similar in both sexes...................................... Lissoporcellana Haig, 1978 View in CoL