Macrophthalmus (Euplax) H. Milne Edwards, 1852

Barnes, R. S. K., 2010, A Review Of The Sentinel And Allied Crabs (Crustacea: Brachyura: Macrophthalmidae), With Particular Reference To The Genus Macrophthalmus, Raffles Bulletin of Zoology 58 (1), pp. 31-49 : 37

Macrophthalmus (Euplax) H. Milne Edwards, 1852

( Fig. 1B )

Small to medium-sized (<25 mm carapace breadth); corneas reduced, ocular peduncles elongate but not projecting beyond lateral carapace margins, much longer than breadth of front; front narrow but not constricted between bases of ocular peduncles, where its breadth is ca. 15% the distance between external orbital angles; ischium of external maxilliped> 1.7 times length of merus; carapace with breadth ca. 1.3 times length, with lateral margins converging anteriorly, so that greatest carapace breadth occurs posterior to anterolateral teeth, with small, blunt anterolateral teeth, without specific system of rows or clumps of granules or hairs on branchial regions; central region of posterior border of epistome concave; fingers of male cheliped short with index straight or slightly upcurved and with differentiated teeth on both dactylus and index. Shallow subtidal.

Euplax contains two species: M. leptophthalmus (H. Milne Edwards, 1852) (type species) and M. dagohoyi Mendoza & Ng, 2007 . The name M. gastrodes Kemp, 1915 , was considered by Barnes (1977) to be a synonym of M. leptophthalmus , a view shared by Mendoza & Ng (2007), but Ng et al. (2008) list it, presumably erroneously, as a valid species within the subgenus Venitus (below). The separation of this subgenus from Venitus is discussed by Mendoza & Ng (2007).

Figures

Fig. 1. Form of the carapace and adult male chela of subgroups of the genus Macrophthalmus I: (a) subgenus Chaenostoma, (b) subgenus Euplax and (c) subgenus Hemiplax. Scale bars = 5mm.