Barnes, 1967
Carapace moderately wide; front moderately to strongly narrow, more or less constricted basally; lower orbital border fringed with medium-sized granules (except male of M. tomentosus, in which lower orbital border bears lobulate tubercles); antero-lateral teeth broad based, rectangular; branchial region with conspicuous longitudinal ridges or line represented by row of setae, without clumps of granules. Postero-median margin of epistome usually concave, anterior buccal cavity deeply depressed below or slightly elevated medially. Ocular peduncles more than half of carapace length in adult, narrow, cornea reaching base of external orbital tooth. Carapace without intestinal ridge. Male abdomen with sixth segment usually not expanded proximally; female telson moderately wide, distolateral margins variable, basal margin considerably convex. Third maxilliped with merus distinctly shorter than ischium, both well sculptured. In males, inferior ridge on outer surface of palm poorly developed; fingers moderately short, fixed finger more or less deflexed; merus lacking stridulating crest on anterior margin. In females, palm of chela relatively shallow, without longitudinal granular row on outer surface; inferior ridge weak, submarginal; inferior row of setae usually present. Second to fifth pereiopods moderately stout; merus of second and third pereiopods armed with subdistal tooth proximal to abruptly delimited subdistal groove. (Komai et al., 1995)
Species treated:
Macropthalmus definitus Adams & White, 1849
Macropthalmus pacificus Dana, 1851
Macropthalmus tomentosus Souleyet, 1841