412 Reviews — Prof. Edward D. Cope — 



The volume now noticed is conceived in a systematic spirit. After 

 the preface, which accounts for the origin of the collections, states 

 the rules of nomenclature, and the chief scientific results attained, 

 an Introduction describes the geological succession of Tertiary rocks 

 of Western America, and attempts to correlate, on the evidence 

 of their fossils, the American rocks which contain vertebrata, with 

 those of Europe. If we do not discuss this correlation, it is because 

 it raises questions which would require a volume for their examina- 

 tion ; but we may say that just as the occurrence of fossil reptiles in 

 America nearly allied to those in some European strata seems to us 

 insufficient to fix the age of the American deposits ; so the presence 

 in American strata of extinct species of European genera of Mammals, 

 even when many occur in common, is but uncertain proof of identity 

 in age between the subdivisions of the American Tertiaries and the 

 subdivisions recognized in Western Europe. But if this problem, 

 which is taken up as it were by the way, is not finally solved, facts 

 enough are presented to challenge attention, and justify the correla- 

 tions which are made. 



The first part of the volume discusses the Puerco, Wasatch, and 

 Bridger groups of American fossil vertebrate life. The oldest of 

 these is regarded as Tertiary, rather than as Post-Cretaceous. It 

 is a lower division of the Wasatch series, with a distinct fauna, 

 accumulated in the Wasatch Lake. The Wasatch beds range from 

 New Mexico through Colorado and Wyoming, and consist of sand- 

 stones and marls, which vary from fifteen hundred feet to five 

 thousand in thickness. Very few vertebrate fossils are found in 

 the overlying Green Eiver beds ; but the Bridger group which suc- 

 ceeds has yielded a rich fauna, though the beds are less widely 

 distributed than the older Eocene series. 



The fauna of these beds comprises first, a large number of Fishes, 

 which are observed to have a facies similar to that of the existing 

 fresh waters of the United States, with the addition of two families 

 now confined to the southern hemisphere. Among the Fishes we 

 note a new Elasmobranch genus, Xiphotrygon, which is the genus 

 Try g on with the teeth of Raja. The Lepidosteus type is represented 

 by the extinct genus Clastes, of which four species are indicated. 

 Pappichthys, another genus of these beds, differs from the existing 

 Amia in having one, instead of several rows of teeth on the bones 

 about the mouth, but though founded on mandibles, some of the 

 species are described from vertebra?. The genus RJdneastes is a type 

 of doubtful affinity, characterized by possessing vomerine teeth, and 

 well known from five species. Dapedoglossus is a genus with four 

 species closely related to Osteoglossum. Dlplomystus comprises 

 five species of Herrings, which differ from the genus Clupea in 

 possessing small dorsal scutes in the median line of the back. The 

 Perch type is represented by several genera, defined by the author 

 under the names Erismatopterus, Amphiplaga, Asineops, Mioplosus and 

 Priscacara. Of these genera, perhaps the most interesting is 

 Mioplosus, which is allied to Lehrax and Perca. This fish fauna 

 has more than ordinary interest from its occurrence in beds which 



