Callianideidae

Poore, Gary C. B., 2015, Rediagnosis of Callianideidae and its genera (Crustacea: Decapoda: Axiidea), and description of a new species of Heardaxius Sakai, 2011, Zootaxa 3995 (1), pp. 229-240 : 231

Key to genera of Callianideidae

1. Pleopods 2–5 with marginal filaments; chelipeds strongly dissimilar, minor cheliped cylindrical....................... 2

– Pleopods 2–5 without marginal filaments; chelipeds similar or nearly so, both with flattened articles.................... 3

2. Pleopodal marginal filaments branching or not; male pleopod 1 of 1 article, distally setose, with thumb-like appendix interna........................................................................................... Callianidea

– Pleopodal marginal filaments simple; male pleopod 1 of 1 or 2 indistinct articles, second triangular, appendix interna present as mesial row of hooks....................................................................... Paracallianidea

3. Maxilliped 3 with toothbrush of stiff setae on ischium; uropodal endopod with oblique-transverse row of spiniform setae............................................................................................... Thomassinia

– Maxilliped 3 with only tapering setae on ischium; uropodal endopod without oblique-transverse row of spiniform setae.... 4

4. Rostrum spike-like or sharply triangular; maxillipedal 3 merus with distal tooth, exopod as long as merus........ Crosniera

– Rostrum obsolete; maxillipedal 3 merus without distal tooth, exopod vestigial or absent.............................. 5

5. Gonochoristic; pleopod 2 with appendix interna scarcely exceeding fused appendix masculina; uropodal exopod with dorsal plate or notch.................................................................................. Mictaxius

– Hermaphroditic; pleopod 2 of male with appendix interna well exceeding fused appendix masculina; uropodal exopod evenly ovate....................................................................................... Heardaxius