The genus Meyeria was established by Prof. M'Coy, in 1849, for the reception of certain Crustaceans from the Gault and Greensand, found at Speeton, Yorkshire, and at Atherfield, in the Isle of Wight. A new form has been most obligingly sent to me for examination by Henry Willett, Esq., F.G.S.; and this being in a more perfect state of preservation than any heretofore obtained, enables me to refer to the same species about eight other remains from the Chalk preserved in the British Museum and including the carapace figured on pl. xxxviii. fig. 8 of Dixon's Geology of Sussex.