Note 426 — Chapter XXI · PYCNOGONIDA[393]

The chelate form of the foremost appendages is of little moment. A chela consists merely of a more or less mobile terminal joint flexing on a more or less protuberant penultimate one, and in the Scorpions, in Limulus, throughout the Crustacea, and even in Insects (cf. vol. vi. p. 554), we see such a structure arising independently on very diverse appendages.