The prevailing opinion among zoologists at the present day, with regard to the affinities of the King Crab, is that it must be regarded as one of the Crustacea. Even when this view is not fully accepted the King Crab is placed in a special position of isolation and its relationship with Crustacea strongly insisted upon, whilst more remote affinity with the Arachnida is grudgingly admitted.
My friend Edouard Van Beneden, of Liège, is the only zoologist who has definitely taken a divergent line, and has frankly endorsed the instinctive perception of Straus Durkheim in declaring that Limulus is no Crustacean, but simply and unreservedly an Arachnid. Ed. Van Beneden bases his opinion upon embryological data. I have elsewhere expressed my full concurrence in that opinion, but the grounds upon which my conclusion rests are not solely embryological —they have reference to the structure of the adult Limulus and Scorpion....
