CRUSTACEANS the typical Essex " spiders," as the members of the genus are always found on a sandy or muddy bottom, to which the colour of the crabs almost invariably corresponds.' After discussing some points in the biology of Pisa gibbsii, without definitely stating that it is found in Essex, he notes that ' Pisa tetraodon occurs at the Nore and may be considered an Essex species.' Further on he says that ' the common shore-crab (Carcinus maenas) is very widely distributed and is a well-known Essex form, where its colour is invariably identical with the sandy or muddy bottom on which the creature lives. When however we find it in rock- pools on the granite or serpentine of Cornwall, or on the syenite or basaltic shores of the Channel Islands, this interesting species assumes the most beautiful markings, tinted with really gorgeous colour, and mottled in the most delicate manner. It is often almost impossible to detect the crab in these localities, so perfectly does it resemble its surroundings.' * Mr. Lovett's remarks on the colouring of the shore-crab are novel. As a rule it is only young specimens that display any striking pattern, the adults being in general of a sombre green or, as Leach says, * some- times of a pale green more or less mottled with a darker teint [tint].' 1 Bell gives the colour as blackish green, with the qualification that ' they vary, however, considerably both in the hue and in the intensity of the colour,' * but this is very different from saying that they ever assume the tints of sand and mud. The spider crabs no doubt owe their popular name to the long spindly legs by which many of them show a kind of resemblance to some spiders or to spider-like terrestrial animals. Science groups them in the Oxyrrhyncha, the sharp-beaks, because they have the carapace acutely produced in front. The readiness with which they utilize the resources of the sea, its mud and sand, its weeds, its sponges, its zoophytes, and other objects, for their own purposes of disguise, has long attracted attention. Of late years the wonder has turned to admiration, from the discovery that these crabs are not impassive sluggards, helplessly en- cumbered and overgrown against their will, but active participants in all that happens, each the predominant partner in a diversified yet strictly limited company. On a territory consisting of their own crustaceous covering they plant the garden, arrange the menagery, spread the soil, permit the presence of fixed or moving tenants. By their arts of conceal- ment, though they are pleasing to the palate of numerous and powerful foes, they hold their place successfully in the battle of life. Their move- ments are in general lethargic, but the long claws can be darted out with lightning rapidity to seize the passing prey. To Mr. Lovett's notice of Stenorhynchus rostratus, Mr. William Cole, F.L.S., the editor of the Essex Naturalist, adds the remark that it is also found in the estuary of the Colne. On this same species Dr. H. C. Sorby, LL.D., F.R.S., in manuscript notes on the Crustacea of this 1 The Enex Naturafiit, vol. xi. pp. 252, 253 (1900). 1 MalMoitraca PoJofhthalmata Britaimur, text to pi. J (1816). 1 Brituh Sulk-eyed Cnutacea, p. 77 (1853). 205
