A revision of the species belonging to Pentacladia Westwood is proposed. Chirolophus halidayi Walker and Chirolophus incertus Masi are synonymized with Pentacladia elegans Westwood, a neotype of which is designated. P. matilei and P. mateui spp. nov. are described, respectively from North Africa and Algeria; P. elegans ssp. insularis, a new subspecies, is proposed from the populations present in Corsica and Sardinia, and Pentacladia eques ssp. mauritanica for a female discovered in Mauritania. At last the known species and subspecies are keyed out.