I. on the Syncarida, a Hitherto Undescribed Synthetic Group of Extinct Malacostracous Crustacea; II. on the Gampsonychidæ, an Undescribed Family of Fossil Schizopod Crustacea; III. on the Anthracaridæ, a Family of Carboniferous Macrurous Decapod Cr | lit.salon