Key for the species identification of the Order Aspidochirotida known from northeast Brazil: 1 Gonads in two tufts, one on each side of dorsal mesentery. Tables and C-shaped ossicles present (Family Stichopodidae)...................................................................................... Isostichopus badionotus - Gonads in a single tuft, on left side of dorsal mesentery. Tables present, usually accompanied by buttons, plates or rods, but there are no C-shaped ossicles (Family Holothuriidae)........................................................ 2 2 Ossicles of the body wall are rosette-like elements........................................... Actinopyga agassizii - Ossicles of the body wall of different forms than rosettes (Genus Holothuria)..................................... 3 3 Tables with disc margin knobbed............................................. Holothuria (Cystipus) pseudofossor - Tables with disc margin smooth or spinous................................................................. 4 4 Tables with reduced disc............................................... Holothuria (Semperothuria) surinamensis - Tables with well-developed disc.......................................................................... 5 5 Tables accompanied by irregular buttons (indented or knobbed) or regular buttons (knobbed)......................... 6 - Tables accompanied by smooth buttons or delicate perforated plates............................................. 8 6 Buttons irregular or complex, not knobbed on surface......................................................... 7 - Buttons regular, knobbed on surface........................................... Holothuria (Holothuria) dakarensis 7 Buttons complex, similar to fenestrated plates, with parallel perforations. Tables large in tube feet............................................................................................... Holothuria (Theelothuria) princeps - Buttons irregular, with perforations usually alternating. Large tables absent in tube feet.... Holothuria (Platyperona) parvula 8 Tables small, accompanied by smooth plates, with 2–4 central perforations and a few smaller perforations surrounding these, without buttons............................................................... Holothuria (Halodeima) grisea - Tables with semicircular discs with 4–8 marginal perforations and a small spire, small and smooth buttons........................................................................................ Holothuria (Thymiosycia) arenicola

Published as part of Prata, Jéssica, Manso, Cynthia L. C. & Christoffersen, Martin L., 2014, Aspidochirotida (Echinodermata: Holothuroidea) from the northeast coast of Brazil, pp. 127-150 in Zootaxa 3889 (1) on page 129, DOI: 10.11646/zootaxa.3889.1.8, http://zenodo.org/record/229183