Here it seems that we are at last getting a refreshing breath of true science; but if carried out in its entirety how shall we assure ourselves that in the long ago very diverse types of fossils, e.g., gratolites and nummulites, or even trilobites and mammals, =could not have been contemporary with each other=? This principle of "rock facies," if incorporated into the science in its early days, would have saved the world from a large share of the nonsense in our modern geological and zoological text-books. But in answer to any pleadings about the imperfection of the record, or any protests about the injustice of judging all the life-forms of an "age" by a few examples of local character, i.e., of fresh, shallow, or deep water as the case may be, the very obvious retort is, Why then are such local and fragmentary records given =a time value=? Why, for example, should the Carboniferous and associated formations be counted as representing all the deposits made in a certain age of the world, when we know from the Cambrian and Silurian and also from the alleged "subsequent" Jurassic that there must have been vast open sea deposits formed contemporaneously? As Dana expresses it: "The Lias and Oolyte of Britain and Europe afforded the first full display of the marine fauna of the world since the era of the Subcarboniferous. Very partial exhibits were made by the few marine beds of the Coal measures: still less by the beds of the Permian, and far less by the Triassic. The seas had not been depopulated. The occurrence of over 4,000 invertebrate species in Britain in the single Jurassic period is evidence, not of deficient life for the eras preceding, but of extremely deficient records."[44]