Johannes Govertus de Man, was a Dutch biologist. He was assistant curator at the Rijksmuseum van Natuurlijke Historie in Leiden, where he specialised in free-living nematodes and decapod crustaceans, although he also wrote papers on flatworms, sipunculids and, in his dissertation only, vertebrates. His change away from vertebrates disappointed the director of the museum, and de Man left his job there after eleven years. For the rest of his life, de Man worked at his parents' house in Middelburg and later at a house near the shore at Yerseke in the Oosterschelde estuary, relying on his family's private income.
Sidney Irving Smith was an American zoologist.
In the 10th edition of Systema Naturae, Carl Linnaeus classified the arthropods, including insects, arachnids and crustaceans, among his class "Insecta". Wingless arthropods were brought together under the name Aptera.
Around 65 species of crab occur in the waters of the British Isles. All are marine, with the exception of the introduced Chinese mitten crab, Eriocheir sinensis, which occurs in fresh and brackish water. They range in size from the deep-water species Paromola cuvieri, which can reach a claw span of 1.2 metres, to the pea crab, which is only 4 mm (0.16 in) wide and lives inside mussel shells.
