Petrolisthes Stimpson, 1858

Petrolisthes Stimpson, 1858: 227 .

Type-species. Porcellana violacea Guérin, 1831 [by original designation].

Key to species known from Brazil

1. Carapace with transverse piliferous striations, interrupted at grooves delimiting regions.............................. 2

- Carapace nearly smooth, some striation on posterolateral region................................................ 3

2. Single strong epibranchial spine on carapace. Gape of cheliped fingers thickly pubescent, palm with convex extensor margin........................................................................................... P. galathinus

- Two strong epibranchial spines on carapace. Gape of cheliped fingers not pubescent, palm with nearly straight extensor margin.......................................................................................... P. rosariensis

3. Both inner and outer orbital angles not produced; ocular peduncle not pubescent next to the cornea............. P. armatus

- Inner and/or outer orbital angles produced into small and acute spine; ocular peduncle fringed with short simple setae next to cornea............................................................................................. 4

4. Inner orbital angle produced into acute spine. Propodus of cheliped smooth, gape of fingers pubescent on ventral surface................................................................................................ P. amoenus

- Inner orbital angle not produced. Propodus of cheliped with longitudinal crest, gape of fingers not pubescent on ventral surface.......................................................................................... P. marginatus