Maja Lamarck 1801, s. str.

1. Supraorbital eave relatively broad, as wide as long; dorsoanterior surface of carapace with 2 unarmed, relatively smooth dark oval window-like patches, one on each side of gastric region (Figs. 6A, B, 36E); ischium of third maxilliped ca. 1.5 times as long as wide (Fig. 43F); Mediterranean and adjacent Atlantic waters............................... Maja crispata Risso, 1827

– Supraorbital eave relatively narrow, longer than wide; dorsoanterior surface of carapace evenly granulated, without any unarmed or ovate patches (Figs. 4, 36A–D); ischium of third maxilliped twice as long as wide (Fig. 43A–E); eastern Atlantic to western Indian Ocean.........................................................2

2. Carapace of adults longer than wide; adult pseudorostral spines subparallel; restricted to Mediterranean (Fig. 36A).................................................................. Maja squinado (Herbst, 1788)

– Carapace of adults rounded, as long as large; adult pseudorostral spines diverging, forming a V (Fig. 36B–D); Atlantic to South Africa.......................................................................................3

3. Spines of lateral carapace margin relatively short; antorbital spine almost straight (Figs. 4C–F, 36B, C); northern Atlantic to mid-Atlantic...................... M. brachydactyla (Balss, 1922)

– Spines of lateral carapace margin relatively long; antorbital spine curved (Figs. 5, 36D); southern Atlantic to South Africa........................................................... M. cornuta (Linnaeus, 1758)