Key to genera of Expanathuridae

1. Pereopods 1–3 only slightly differentiated from posterior pereopods, propodi not swollen; pleopod 1 rami fused in juveniles; female pereon and pereopods covered with long setae, body becoming extremely elongate after spawning ..................................... ............................................................................................... Eisothistos Haswell, 1884

­ Pereopods 1–3 well differentiated from posterior pereopods, propodi swollen; pleopod 1 rami free; female pereon and pereopods not covered with long setae, never elongate ...................................................................................................................................... 2

2. Pleonites 5 and 6 not longer than pleonites 1–4; pleonite 6 clearly fused dorsally to telson; uropodal exopod a simple narrow leaf ....... Coralanthura Poore & Kensley, 1981

­ Pleonites 5 and 6 longer than pleonites 1–4 or all pleonites fused; pleonite 6 usually marked off dorsally from telson; uropodal exopod broad or complex ......................... 3

3. Uropodal exopod with spike­like dorsal lobe, rami and telson with dentate margins. 4

­ Uropodal exopod with obsolete dorsal lobe, rami and telson with entire or dentate margins...........................................................................................................................6

4. Uropodal exopod spike shorter than proximal plate; mandibular palp with 3 articles; maxillipedal endite absent ................................................ Heptanthura Kensley, 1978a

­ Uropodal exopod spike shorter or longer than proximal plate; mandibular palp with fewer than 3 articles; maxillipedal endite present ....................................................... 5

5. Telsonic apex tapering to point from midpoint; mandibular palp of 2 articles; maxillipedal palp broad ............................................................. Rhiganthura Kensley, 1978a

­ Telsonic apex apically rounded; mandibular palp of 1 seta only; maxillipedal palp acute ........................................................................................... Minyanthura Kensley, 1982a

6. Pereopod 1 propodus broader than that of pereopod 2, strongly tapering, obscurely dentate proximally; male antenna 1 flagellum with basal article short and with numerous aesthetascs .................................................................... Expanathura Wägele, 1981

­ Pereopod 1 propodus similar to that of pereopod 2, scarcely tapering, palm smooth; male antenna 1 flagellum with rows of aesthetascs on all articles.................................. ................................................................................................ Panathura Barnard, 1925