Where, for instance, in the modern seas, will we find the remains of polyp-corals now being intercalated between beds of clays or sands over vast areas, as we find them in the Lias and Oolyte of England and elsewhere? Corals require a definite depth of water, neither too deep nor too shallow, but it must be clear and pure; and nothing but some awful catastrophe could place a bed of coral remains a few feet or a =few inches= in thickness over the vast areas that we find them. Crinoids require the same clear, pure water, but much deeper, some of the modern kinds living =over a mile down=, but every student of the science knows that the Subcarboniferous limestone of both Europe and America (called Mountain Limestone in England), so noted for its crinoids and its corals, is constantly found intercalated between shale or sandstone, or between the coal beds themselves as at Springfield, Ill., or in the Lower Coal Measures of Westmorland County, Pa. There are of course, here and there, great masses of these rocks which represent an original formation by growth _in situ_; but no sane man can say this for these great sheets perhaps =only a few inches= in thickness, for in many cases they show a stratified or bedded structure just as much as a sandstone or a shale. In some tables given by Dana on pp. 651-2 of his "Manual," compiled from four different localities, I count no less than =23 beds= of limestone thus intercalated, though we are not told how many of them contain corals or crinoids. Such details are generally omitted as of little consequence. Next, let us try the Lamellibranchs, such as the clam, oyster, and other true bivalves. These creatures have an arrangement in the hinge region by which the valves of the shell tend to open, but during life are held together by the adductor muscles. When dead, however, these muscles relax and decay, and then the valves spread wide open. Of course there are some, such as certain kinds of clams, which burrow in the mud or sand, and the shells of these, if they happened to die a natural death in their holes, could not spread very far apart. However =some mud= must even then wash into their burrows and into their empty shells. But many kinds of bivalves do not thus burrow in the ground; and when the fossils of such kinds are found in quantity with the valves =applied= and often =hollow=, as is so frequently the case in many of the "older" rocks, I cannot see how we are to understand any ordinary conditions of deposit. And yet we are gravely assured by a high authority, that "A sudden burial is not necessary to entombment in this condition."