II. THE ORGANIC REMAINS display the boundless profusion of animal life which prevailed during the cretaceous period. The wealden furnishes no grounds of comparison, as that is simply a local fresh water deposit, and consequently can furnish no test of the general condition of life upon the surface of the globe. But when we go back to the oolitic period we obtain a standard by which to measure the doings of nature in the interval, what new creations started into being, and what provisions were made for their subsistence. The state of the temperature cannot be determined, as the products, with the rarest possible exceptions, are wholly marine, and therefore affected by atmospheric influences in a very small degree. Neither can much be conjectured concerning the state of the land, as scarcely a fragment of true terrestrial life has been detected in the deposit; and yet, from the stillness and comparatively small dimensions of sea-basins into which the earthy ingredients were floated, the probability is that the land was both lofty and widely extended. One mammalian, and the remains of a solitary bird, and a meager sprinkling of vegetables, constitute the whole, and even dubious, amount of contributions from this department of nature. To Neptune, therefore, the palæontologist turns his undivided attention; and, comparing one period with another, he finds the following results: The cretaceous deposits all lie WITHIN THE AREA of the oolites. They are _conformable_ generally in position, and display, in proportion to their extent, a like superabundance of calcareous earth. Hence a return to polyp and shelly types of life, which we find so characteristic and diversified in both epochs.