"The terminology which has been introduced in the innumerable monographs of special fossil faunas in the majority of cases makes only the slenderest pretext of any connection with recent systematic zoology; if there is a difficulty, then stratigraphical arguments are made the basis of a solution. Zoological students are as a rule too actively engaged and keenly interested in building up new observations to attempt to spell through the arbitrary palaeontological conclusions arrived at by many stratigraphers, or to revise their labors from a zoological point of view." Hence I have no reluctance in saying that, in the present confused state of the science, it is utterly impossible to find out the truth as to how many hundreds of these "genera" of the Paleozoic rocks may have survived to the present, though having skipped perhaps all the formations of the intervening millions of years. I doubt not that the number is enormously large, though as I have not attempted "to spell through the arbitrary palaeontological conclusions" scattered through the literature, I can only depend on a few though striking examples that lie on the open pages of the ordinary text-books. The larger mammals can of course furnish us no examples, for the "age" in which they abounded is quite conveniently modern, and is separated from the present by no great lapse of time. Of the smaller marsupials, quite a number of jaw-bones have been found in the Jurassic and Triassic, one from the latter being strikingly like the living _Myrmecobius_ of Australia. They are scarcely more numerous in the Cretaceous of America, while in the foreign rocks of this system Dana says that "Only one species had been reported up to 1894." Those strange, sad-eyed creatures called Lemurs deserve a passing notice, for though now confined as to their typical forms to the island of Madagascar, their fossils seem as exclusively confined to the temperate regions of the New and the Old World. Flower and Lydekker enumerate about fifteen fossil species, and add that: "... it is very noteworthy that all these types seem to have disappeared from both regions with the close of the upper portion of the Eocene period."[45]