But the Devonian "age of fishes" (Devonian including old red sandstone) was far too important a period to be thus got rid of; and it is difficult to understand _why_ the narrative should exclude all the extensive and beautiful (though often little specialized) orders of marine life--all the Corals, the Mollusca and Articulata, which had long abounded--especially some of the Crustaceans, not an unimportant group of which (_Trilobite_[1]) had also culminated and almost passed away before the Devonian; to say nothing of the fact that _land_ "creeping things" (scorpions among _crustacea_, and apparently winged insects) had occurred. [Footnote 1: It is remarkable that the Trilobites rapidly culminated, so that we have the largest and most perfect forms, such as _Paradoxus_, with the lowest (_Agnostus_) in the same beds in Wales (Etheridge's "Phillips' Manual," Part II. p. 32).] It is a special difficulty also, that if _insects_ are included among the "creeping things" of the _earth_ then various families of the "land-creation" (sixth day) became represented _before_ the great reptiles of the "water-creation" (fifth day). The fact is that a glance at the subjoined Tables (which are only generally and approximately correct) will suffice to show how the main features of the progress of life-forms differ from what is required by the older methods of reading Genesis. To reduce the table within limits, I have grouped together all the lower forms of life in the animal table, viz., the sponges, corals, encrinites, and molluscs. It is sufficient to say that these appear in all the rocks except the very oldest--the Caelenterata beginning, and the Molluscoids exhibiting an early order in _brachiopoda_, which seems to be dying out. Crustaceans and insects appeared as early as Silurian times. The idea of successive "kingdoms" or "periods," each of which was _complete_ in its actual fauna upon earth before the next was fully ushered in, can no longer be defended. It is in the _completion_ of one class of life before the other, that the fallacy of the period theory lies--for completion is essential to that theory which supposes "the Mosaic author" to have intended to describe the _process of production on earth_. But it is quite impossible to deny that there _is_ a certain observable movement and gradual procession in the history of life which is exactly consistent with what is most likely to have happened, supposing the Divine designs of life-forms were first declared in successive order at short intervals of time, and then that the processes of nature worked out the designs in the fulness of time and gradually in order, each one _beginning_ before the next, but only beginning.