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��8, Niederschoena, Saxony, Hungary. Some of these districts are exceedingly vague ; ' Qua- dersandstoDe/ for example. Niederschoeaa is in Saxony ; and Quedlinburg is in the Harz district, at the same borizon as Blankenburg, which is not Cenomnnian at all, but Senonian. From all these sources lie enumerates 442 species, — a number which is still too small. The Dakota group alone furnishes 19b species.

The second division of the work relates to the Laramie group, hut does not review its flora. Some dozen additions to it. made by Mr. Lakes at Golden, Col., are described, six of which are new species. Mr. Lesquereux here discusses again the geological position of this group, and, while still insisting upon ita eocene character, admits that its flora re- sembles that of the travertines of Si^zanne in the Paris basin, but which arc known to lie considerably lower than the coarse limestone and lignites that prevail in that diatrict. In his table of distribution he only enumerates 207 species ; but the reason for this paucity is his failure to recognize as Laramie the plants described from the Fort-Union group, — the upper Missouri and lower Yellowstone r^on, and the Bad lands of Dakota.

The third division of the work consists of an exhaustive survey of the flora of the Green- River group ; and, as this had not previously been done, it forms altogether the most valu- able part of the treatise. Since the ap|>ear- ance of the ' Tertiary flora,' a large amount of material from this formation had accumulated in the author's hands, out of which he obtained DO less than ninety new species. The most fertile source of this material was the small locality in South Park, Col., known as Floris- sant, from which, in a light volcanic ash, also containing insect^remains, an immense numt)er of beautifully presen-ed specimens of fossil plants have been derived. The other principal localities grouped nnder the general designa- tion of ' Green-River group,' are those of Green-River Station and Alkali-Stage Station, Wyoming; Elko Station, Nev, : and n place reported as in ' Randolph county.' As to this lost, as there appears to be no Randolph county in any western territory, it is probable that Randolph courtiiouse. Rich county, Utah, is meant, which is the same as is otherwise known as Bell's Fish-Cliff, where fine speci- mens of palm-leaves and other fossil plants are found. The locality called Barrel's Springs is also here referred to the Green-River group, although it appears in the preceding table as belonging to the Laramie group. This is con- fusing, to say the least.

��We have not space to show how the floraa of these several localities are correlated by the author; but the occurrence of identical and wholly characteristic species in several of them seems to establish their geological synchrony with considerable certainty. This formation is now commonly reganied as eocene ; but Mr. Lesquereux, led, as In the case of the Laramie, by the affinities of the flora with that of Europe, insists upon placing it somewhat higher, and calls it ' oligocene.'

The remainder of the work is devoted to what is called the ' miocene flora.' So far as the localities on the Paciflc slope (Chalk Blufls and Corral Hollow, Cal. ; John Day valley. Ore. : and Alaska) are concerned, this refer- ence is doubtless correct ; but the large collec- tions from the ' Bad lancb of Dakota ' belong almost without question to the Foil.- Union group, and should have been referred to the Laramie, with which the invertebrate fauna forces us to correlate that group. It is true that this flora has a marked miocene aspect when compared with those of European strata, and that several species seem to have persisted from that period to the present (e.g., Corylua Americana, Onoclea sensibilis) ; but the entire Laramie flora is also strongly miocene, and at least one species (Ginkgo biloba, L.) of the living flora has come down to us seem- ingly nuclmnged from the typical Laramie of Point of Rocks, Wj-oming.

Geological considerations aside, this volume is one of the most important that have lately appeared upon the paleontology of western America, and, should it prove his last work, would fittingly crown the long and faithful labors of its justly celebrated author.

��ANTHONY AND BRACKETT'S PHYSICS.

For many years the English have borrowed or stolen their text-books .of elementary phys- ics from the French, and Americans have borrowed or stolen from the English. About a year ago, Daniell produced a distinctly Eng- lish, or rather distinctly Scotch, book of this order. Now Professors Anthony and Brackett have undertaken to remove America's reproach. Their book is to consist of two parts, of which part i., ' Mechanics and heat,' has already ap- peared. It is a small volume, and in other respects shows a disregard of old traditions. It has numerous diagrams, but hardly aptcture,

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