into the crevices with great rapidity when disturbed. Though not pelagic, their flattened legs enable them to swim very well. They vary in colour from a deep green with faint yellow streaks to a bright yellow and red. Coast of Australia, New Zealand, Norfolk Island, California, and Chili.
19. Pachygrapsus transversus (Gibb.).—Inhabits short seaweed about midway between high- and low-tide marks. It is also obtained in crevices of rocks amongst small stones, and amongst sessile ascidians. In appearance it is something like a small specimen of G. variegatus, but may be at once distinguished by the bristles which clothe the legs. Port Jackson.
20. Cyclograpsus Lavauxi (M.-Edw.).—Common round Port Jackson in situations where the shore is covered with clean stones—i.e. stones free from algæ and mud—nearly at the limit of high tide. They are very interesting, especially in the operation of disengaging them from your fingers, which is no easy matter if they once get a good grip. The colour is a beautiful red dorsally, with white on the ventral side. Port Jackson.
21. Chasmagnathus lævis (Dana).—Found as a rule in muddy situations wherever there are stones, under which it burrows. It also avails itself of the burrows made by Macrophthalmus setosus. Colour deep brown, dotted on the carapace with yellow. Port Jackson.
22. Sesarma erythrodactyla (Hess.).—The observer will be at once struck with the great disparity in coloration between the male and female. The female is always a dull brownish colour, while the male exhibits great variation, the carapace being sometimes a brilliant green. The chelse in both sexes are tipped with red. Common on mud-flats under stones. Port Jackson.
23. Plagusia chabrus (Miers).—This species inhabits the short red seaweed which clothes the rocks just below low-tide mark. It is very seldom seen to leave the water of its own accord, but, if it does so, returns almost immediately. It subsists chiefly on vegetable matter (Fucus and algæ), but consumes animal matter whenever it is available. The outstretched limbs cover an expanse of about 10 in. The carapace and dorsal aspect of ambulatory limbs are covered with a short dense red pubescence. Widely distributed: Port Jackson, New South Wales; Tasmania, New Zealand, Cape of Good Hope, and Chili.
