Phasmon gen. nov. Figs 1, 2, 3, 4

Type species.

Phasmon typhlops, by present designation.

Diagnosis.

Small sized (carapace width less than 30 mm). Carapace 1.6 × wider than long; fronto-orbital width about twice width of posterior margin; dorsal surface weakly convex (Figs 1, 2A); frontal margin weakly sinuous, continuous with supraorbital margin, forming almost straight anterior margin of carapace in dorsal view (Fig. 1); postorbital and epigastric cristae almost indiscernible (Figs 1, 2A); orbit shallow, eyes vestigial, almost immovable, length about half orbital width; cornea reduced, unpigmented, facets absent; external orbital angle very wide, confluent with anterolateral margin (Figs 1, 2A). Epibranchial tooth inconspicuous. Median lobe of epistome broadly triangular (Fig. 2A). Maxilliped 3 ischium length less than twice width; exopod reaching beyond distal edge of ischium, flagellum well-developed (Fig. 3A). Cheliped fingers without gape when closed (Fig. 3D, E). Male anterior thoracic sternum very wide, around 2.3 times as wide as long (Fig. 2B). Male pleon triangular (Fig. 2C). G1 tapering anteriorly, tip narrow but blunt (Figs 3C, 4A, B). G2 distal segment tip pointed (Figs 3B, 4C, D). Female vulvae on sternite 6, reaching sutures of sternites 5/6 anteriorly, very widely spaced from one another (Fig. 2F).

Etymology.

The genus name is an arbitrary combination of the Latin word “phasma”, meaning ghost, which refers to the type species’ pale appearance and dark habitat, and the genus name Potamon, which is the type genus of the family. Gender neuter.