Gonoplax sinuatifrons Miers 1885: 588; 1886: 246, pl. XX, fig. 2.

Remarks. Castro (2007) erected the monotypic Hadroplax to accomodate Gonoplax sinuatifrons Miers. In his synonymy he listed G. sinuatifrons (Miers 1885: 588) as a nomen nudum. The description of G. sinuatifrons by Miers (1885) stated “... very nearly allied to the common European Gonoplax rhomboides, and distinguished only by the sinuated frontal margin and shorter chelipeds”. This brief description makes the species name available and the “sinuated frontal margin” is among the characters listed by Castro (2007: 697) in his description of Hadroplax: “front slightly deflected ventrally, sinuous.”

Valid as Hadroplax sinuatifrons (Miers, 1885) .