In the year 1865 I noticed the occurrence of what appeared to be a sessile Cirripede from the Upper Chalk of Norwich, and referred it to Leach's genus Pyrgoma. For this unique example the name of Pyrgoma cretacea was then proposed, and afterwards, in 1868, it was more fully described and figured by me in the GeologicalMagazine. I also pointed out that Charles Darwin, in his Monograph on the Fossil Cirrepedia, had described a fossil form belonging to this genus under the name of Pyrgoma anglicum, from the Coralline Crag of Ramsholt, Suffolk, a species found living off the south coast of England and of Ireland, Sicily, Madeira, Cape de Verde Islands, etc.; while Michelotti had named, but not described, a species (Pyrgoma undata) from the North Italian Tertiary strata.

The problems of life which the biologist is called upon to solve present so many and such varied aspects that they are never likely to become exhausted, or to weary by reason of their monotony. Among these the appearances and disappearances of groups in time (like the players on Shakespeare's mimic stage) are certainly not the least interesting questions awaiting solution.

The paper is divided into two parts, viz.:—

1. Sedimentary Rocks.

2. Igneous and Metamorphic Rocks.

Some three years ago, on referring to the twenty-fifth volume of the “Beiträge zur Geologischen Karte der Schweiz,” I found Professor Heim had devoted a few pages (pp. 316–319) of that work to my criticisms of his attempts to prove that Jurassic rocks had been metamorphosed into schists containing authigenous garnets, staurolites, etc. Had he brought forward any new fact of importance or pointed out any serious error in my work I should have replied at once, but as he was unable to do this, and as the justice of one of my criticisms was indirectly admitted in the petrographical appendix by Dr. C. Schmidt, I allowed more pressing and interesting matters to take precedence of one which had become chiefly personal.

When man first began the study of the earth's surface, he encountered at the very beginning, along the borders of the sea-coasts, on the lowland plains, and even on the hills, certain puzzling phenomena, difficult of explanation. These perplexing observations seemed to testify, by means of ancient raised beaches, fossil oyster and mussel shells, dessicated salt marshes, fragments of wrecks, and even by ancient anchors in the hills, that at some unknown time in the past the sea had “formerly been where the land now was.”