Telson armed usually with 3 pairs of spinules

Adrostral sulcus as wide as post-rostral carina

Telson armed with 3 pairs of movable spines

Adrostral carina and groove long, extending almost to posterior margin of carapace, the groove wide

Gastrofrontal crest present

Gastrofrontal groove bifurcate posteriorly

Petasma with distomedian projection reaching to or slightly overhanging distal margin of costae,

Ventral costae largely broadened apically unarmed on their free border but incised on thier attached border

Outer surface of lateral lobes not tuberculate

Thelycum with lateral plates their anteromedian angles divergent

Anterior process with anterolateral edge raised forming 2 subtriangular or cylindrical projections

posterior process triangular, its anteior edge raised

Its lateral ridges delimiting a median depressed area

Telson unarmed

Adrostral crest and groove long, extending almost to posterior margin of carapace, the groove wide

Last abdominal segment colour bands reaching the ventral margin

Petasma with short distomedian projections, reaching or slightly overhanging distal margin of costae.

Ventral costae broadened apically and bearing minute spinules at tip, outer surface of lateral lobes not tuberculate

Thelycum with lateral plates, their anteromedian margins diverging, then turning in a broad arc continuous with anterolateral margins

Anterior process triangular, anterior edges raised in lateral ridges delimiting a median depressed area.