Excluding the hermit crabs, 58 species of Crustacea Anomura belonging to six families have been recognised from the state of Western Australia. There are 21 genera, of which ten are Indo-West Pacific only and 11 are shared with the Eastern Pacific and Atlantic.

Seven of the species are temperate forms and Australian endemics. One of these is monotypic; two have their closest relative in New Zealand; and four have their affinities with tropical Indo-West Pacific species.

Two species are larger and more abundant in the warm-temperate region but range well into the tropics, including areas outside Australia.

The remaining 49 species are strictly tropical members of the Indo-West Pacific fauna, and most are of wide distribution. Some are confined to the tropical coast of Western Australia, while others penetrate the warm-temperate province.

Twenty-four tropical species extend throughout all or most of the Indian Ocean. Seven of these have their eastern limit in Australia and the Indo-Malaysian region; 17 extend northward to Japan and/or eastward to Oceania.

Five tropical species extend westward only to the central sector of the Indian Ocean. Of these, three are confined at the eastern limit of their range to Australia and Indo- Malaysia, while two range northward to Japan.

Three species occur only in the eastern sector of the Indian Ocean; all extend northward to Japan and eastward to Oceania. Seventeen species have the western limit of their range in Western Australia, and occur nowhere else in the Indian Ocean. Seven of these are apparently endemic in tropical Australia. Five are confined to Indo-Malaysia; three extend northward to Japan; and two extend eastward to Oceania.