The Second Edition of Prof. Morris's “Catalogue of British Fossils” appeared in 1854, and in the same year was published Dr. Chr. G. Ehrenberg's “Mikrogeologie,” containing the figures of numerous Foraminifera found by that eminent German mioroscopist, in specimens of Chalk from Gravesend, Kent. A preliminary notice, indeed, of these had been given in the Transactions of the Berlin Academy of Sciences for 1838 (1839), pp. 92, 133–135, 146, pl. iv., fig. IV.; and some of the species were quoted in the “Catalogue;” but a more matured consideration was subsequently given them; and, together with many others from other sources, recent and fossil, they were most carefully figured and enumerated in the abovementioned magnificent work on Microzoa. In its fine folio plates, so richly illustrating the Foraminiferal faunæ of many localities, and of many geological horizons, the artistic work is of high order in the zoologist's eyes; it is faithfully correct as to form, aspect, ornamentation, colour, and all details, modified, however, by the specimens being mostly seen as transparent objects, with the thickness of the walls rather too much pronounced at the edges; the objects, too, are some-what in perspective. It being difficult to combine transparency and perspective in a drawing, especially with the attending minutiæ of pores, tubercles, ridges, internal septa, septal apertures, and other characteristics of Forminifera, the result is that the task of recognizing the real zoological place of the figured forms is difficult, or imposible, except to those who have long studied similar hosts of microzoa, similarly mounted in Canada-balsam. Having had such advantages, we feel called on to add to the list of British fossils, with our own nomenclature, the Cretaceous Foraminifera of Gravesend, figured by Ehrenberg.