Review of grapsoid families for the establishment of a new family for Leptograpsodes Montgomery, 1931, and a new genus of Gecarcinidae H. Milne Edwards, 1837 (Crustacea, Decapoda, Brachyura, Grapsoidea MacLeay, 1838) Author Guinot, Danièle Institut de Systématique, Évolution, Biodiversité (ISYEB), Muséum national d’Histoire naturelle, CNRS, Sorbonne Université, EPHE, case postale 53, 57 rue Cuvier, F- 75231 Paris cedex 05 (France) guinot @ mnhn. fr (corresponding author) guinot@mnhn.fr Author Ng, Ngan Kee Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543 (Republic of Singapore) dbsngnk @ nus. edu. sg dbsngnk@nus.edu.sg Author Rodríguez Moreno, Paula A. Direction générale déléguée aux Collections, Muséum national d’Histoire naturelle, case postale 30, 57 rue Cuvier, F- 75231 Paris cedex 05 (France) martin-lefevre @ mnhn. fr Dedicated to the memory of Michael Türkay (1948 - 2015) lefevre@mnhn.fr text Zoosystema 2018 2018-12-21 40 26 547 604 journal article 9255 10.5252/zoosystema2018v40a26 2697b081-f3fa-4256-a62d-f084ee352b1c 1638-9387 4336858 urn:lsid:zoobank.org:pub:E018714D-7CCF-4AB8-A88A-EF033530CA75 Genus Gecarcoidea H. Milne Edwards, 1837 TYPE SPECIES. — Gecarcoidea lalandii H. Milne Edwards, 1837 (see N. K. Ng et al. in press) by monotypy. OTHER SPECIES. — Gecarcoidea humei (Wood-Mason, 1874) ; G. natalis (Pocock, 1889) (see Lai et al. 2017 ). All from the Indo-West Pacific. DIAGNOSIS FIG. 6. — Ventral view of Gecarcinidae to show front, proepistome, cephalic appendages, orbit and mxp3: A , Discoplax longipes A. Milne-Edwards, 1867 , ♂ 32.4 × 37.2 mm, Loyalty Islands, Lifou, Inegoj Cave, MNHN-IU-2008-11402 (= MNHN-B24815); B , Cardisoma guanhumi Latreille in Latreille,Le Peletier,Serville & Guérin,1828 ,♂ 56.5 × 68.0 mm,Antilles,MNHN-IU-2013-14983 (=MNHN- B12270); C , Tuerkayana aff. hirtipes ( Dana, 1851 ) n. comb. , ♂ 61.0 × 79.0 mm, Loyalty Islands,Lifou Island,We cave,MNHN-IU-2017-8397 (=MNHN-B24811); D , T. celeste ( Ng & Davie, 2012 ) n. comb. , ♂ 44.4 × 52.2 mm, Australia, Christmas Island, ZRC 2012.0171; E , T. magnum ( Ng & Shih, 2014 ) n. comb., ♂ 49.0 × 58.7 mm, Indonesia, Java, ZRC 2017.0252. Scale bars: 10 mm. Proepistome as small plate inserted under the lower frontal margin ( Fig. 7H ) ( Tavares 1989 : fig. 7); male gonopore emerging far from P5 coxo-sternal condyle ( Fig. 7G ); thoracic sternum ( Fig. 7 E-G) with sternite 1 as very small, narrow tooth, not separated by suture from sternite 2; sternite 2 developed, semi-ovate; suture 2/3 V-shaped; no suture 3/4, no lateral trace; completely fused sternites 3+ 4 with straight, obliquely directed lateral margins, thus not restricted at level of P1; sternite 8 not developed medially, the triangular posterior emargination reaching sternite 7 at level of thick median bridge at level of suture 7/8; suture 7/8 short; median line only on sternite 7, with its distal part bumping at level of suture 6/7 into weak median bridge that superficially units both sides of the sternal plate and becomes the bottom of the sterno-pleonal cavity ( Fig. 7F, G ); no portion of sternite 8 dorsally exposed when pleon is folded; locking button as large prominence occupying half proximal part of sternite 5, close to suture 4/5 ( Fig. 7F ), surrounded by setae (no delineated pleonal socket); on sternite 4 a thickened region forming hook-like edge close to suture 4/5 ( Fig. 7F ), resembling a clasping apparatus or safety catch, however apparently not functional (described by Guinot 1979: 153 , as “cran d’arrêt” in some Uca sensu lato , and later recognised as a key innovation for the recognition of several distinctive genera within Uca sensu lato , see Beinlich & Hagen 2006 : fig. 3b, c; Köhnk et al. 2017 : fig. 19e). Numerous oblique rows of tubercles covering subhepatic region, but no known report in the emission of stridulation Pterygostomial region glabrous, as in Gecarcinus and Johngarthia . Dense tufts of hydrophilic setae located along margins of pleon and at its junction with carapace in Gecarcoidea ( Fig. 7 E-G), G. natalis and G. lateralis having setal tufts extending along first three pleonal segments and on e P5 coxae, such as in Gecarcinus ( Fig. 7 A-C) and Johngarthia .