Since writing the letter quoted in the foregoing communication by my friend Prof. Liversidge, I have had the opportunity of examining a larger fragment of the calcareous rock to which it refers, and am thereby enabled to add somewhat, not merely to the list of Foraminifera which it contains, but also to the general conclusions to be drawn from it. The lithological characters of the rock are, as Prof. Liversidge has stated, precisely those of many specimens of white chalk, but it is seldom that a Cretaceous mineral is so entirely composed of the recognizable remains of microzoa, and it is still more rarely that a geological deposit occurs, for which so exact a counterpart in process of formation can be indicated. Under these circumstances some further remarks on the subject may not be without interest.