BOOK REVIEWS. 573' 



American cretaceous fauna, as contrasted with that of Europe, is the almost 

 entire absence in our strata of species of Icthyosaurus and Plesiosaurus 

 which abound in many other regions, but we far surpass them in Mesosau- 

 ria and Dinosauria. The American Pterodactyles, also, differed from those 

 of Europe in being larger and having no teeth. Europe carries off the 

 palm for the oldest fossil birds, the oldest American forms being 

 the Odontornithes, or birds with teeth, lately found in the Kansas chalk. 



The Tertiary of Western America comj)rises the most extensive series 

 of fossil vertebrates known to geologists and it was here that the oldest rep- 

 resentative of the horse, the diminutive Eohippus, was discovered and made 

 by Huxley to assume the ajDex of the evolution pyramid, the crowning glory 

 of the theory. 



The most remarkable of the Mammals yet found in America are the 

 TiUodontia, w^hich are claimed to combine the characters of several diff'er- 

 ent groups, viz : the Carnivora, the Ungulata, and the Eodents. 



It is a singular and notable fact that no traces of any xinthropoid Apes^ 

 or of any Old World monkeys have yet been detected in America, Man, 

 however, who doubtless crossed into America by way of Behring's Straits, 

 and at his advent became part of our fauna as a mammal and a primate, 

 has left his bones, and works from the Arctic Circle to Patagonia, principal- 

 ly, however, in the Post Tertiarj^, though there is evidence that he existed 

 in the Pliocene. 



Eegarding the position of man on the earth and among the other mem- 

 bers of the Primate group, the Professor s&js, " the oldest known remains 

 of man on this continent differ in no important characters from the bones of 

 the typical Indian, although in minor details they indicate a much more 

 primitive race. These early remains, some of which are true fossils, re- 

 semble much more closely the corresponding parts of the highest Old World 

 apes, than do the latter our Tertiary Primates, or even the recent American 

 monkeys. Yarious living and fossil forms of Old World Primates fill up 

 essentially the latter gap. The lesser gap between the primitive Man of 

 America and the Anthropoid Apes is partially closed by still lower forms 

 of inen, and doubtless also by higher Apes now extinct. Analogy, and 

 many facts as well, indicate that this gap was smaller in the past. It 

 is certainly becoming wider now with every generation, for the lowest races 

 of men will soon become extinct, like the Tasmanians, and the highest 

 Apes cannot long survive." 



In closing the article he speaks as follows : "If the history of American 

 mammals, as I have briefly sketched it, seems, as a whole incomplete and' 

 unsatisfactory, we must remember that the geological tree of this class has 

 its trunk and larger limbs concealed beneath the debris of Mesozoic time, 

 while its roots doubtless strike so deeply into the Palaeozoic that for the 

 present they are lost, A decade or two hence, we shall probably know 

 something of the mammalian fauna of the Cretaceous, and the earlier 

 lineage of the existing mammals can then be traced with more certainty."' 



