Apex of telson rounded or truncated

Third thoracic sternite produced posteriorly

Procurved tooth absent between bases of 1st pair of pleopod

Procurved tooth absent

Lower antennular flagella with 2 clasping spines

First segment of main branch of lower antennular flagella without triangular projection

Apex of telson triangular

Procurved tooth present between bases of first pair of pleopod

Inner margin of basis of third pereopods with a sharply pointed projection

Third and fourth thoracic sternites deeply channelled longitudinally

Anterior margin of ganital coxae rounded

Petasma without pars estringens

Procurved tooth present between bases of first pair of pleopods

Lower antennular flagella with one clasping spine

Inner margin of basis of third pereopods without a sharply pointed projection

Third and fourth thoracic sternites not channelled longitudinally

Procurved tooth between bases of first pair of pleopods