This chalk drawing by PH Gosse titled ‘Crustacea ii’ depicts 3 different organisms (not to scale). Cyclops (left) is a tiny fresh water copepod, so named for its single eye. Limulus (middle) is a horseshoe crab which is only a rare visitor to European waters. Once grouped with crabs and shrimps in the Crustacea, it is now thought to be more closely related to spiders and scorpions and so sits within the order Xiphosura. Cypris (right) is an ostracod or seed shrimp.
