Arenopontiidae

Key to genera of Arenopontiidae 1. P1 endopod prehensile, enp-1 distinctly longer than exopod; innermost element of P1 exp-3 penicillate.................................................................................................. Arenopontia Kunz, 1937. P1 endopod not prehensile, enp-1 not longer than exopod; innermost element of P1 exp-3 geniculate...................2. 2. P5 of both sexes with innermost element forming a distinct spinous process which is incorporated in the segment.........3. P5 of both sexes with innermost element not modified (occasionally fused at base).................................7. 3. Distal margin of P1 enp-2 with two geniculate setae........................................ Phreatipontia gen. nov. Distal margin of P1 enp-2 with outer naked spine and inner geniculate seta............ Neoleptastacus Nicholls, 1945 .......4. 4. Anal somite with paired spinous processes either side of anal operculum............................. acanthus -group. Anal somite without paired spinous processes either side of anal operculum.......................................5. 5. P1 exp-1 without outer spine; distal segment of P1 exopod with three elements; P2 endopod 1-segmented... trisetosus -group. P1 exp-1 with outer spine; distal segment of P1 exopod with four elements; P2 endopod 2-segmented..................6. 6. Distal segment of P3 endopod with one apical element............................................ australis -group. Distal segment of P3 endopod with two apical elements....................................... spinicaudatus -group. 7. P1 enp-2 with one geniculate seta and one spine; P3 endopod not modified in ♂ .. Mesopontia Sak, Huys & Karaytuğ, 2008. P1 enp-2 with two geniculate setae; P3 endopod sexually dimorphic.............................................8. 8. P2 enp-2 with inner serrate seta; P3 endopod ♂ two-segmented...................... Psammoleptastacus Pennak, 1942. P2 enp-2 without inner serrate seta; P3 endopod ♂ one-segmented............ Onychopontia Sak, Huys & Karaytuğ, 2008.