Published online by Cambridge University Press: 11 May 2009
Many brachyuran megalopae swim with the legs disposed in a curious manner. The chelipeds and first two pairs of walking legs are folded tightly beneath the body, while the two posterior pairs are wrapped over the dorsum, the third pair being stretched out anteriorly, the dactylus, according to its length, touching or being looped round the eye-stalk. It is suggested that this posture gives stream-lining to the megalopa and improves its swimming. The described arrangement has been observed in all but three of some twenty-five species occurring at Plymouth.
In the three exceptions, Corystes cassivelaunus, Thia polita and Pinnotheres pinnotheres (= veterum), all legs are carried folded beneath the body.
Reference is made to previous descriptions of the folding of the legs in the brachyuran megalopa.