94 PROP. J. LOGAN LOBLEY^ F.G.S.^ ETC., ON 



which give to iis at the present di\y ovir highest forms of 

 the vegetable kingdom, and with these tlie plianerogams 

 are also represented abundantly by the gymnospernis that 

 marked the Jurassic epoch. From Westphalia alone 

 fifty-three species of dicotyledonous angiosperms have 

 been obtained from Upper Cretaceous beds. Thtse include 

 species of, amongst othei* genera, Quercus, FopuluK, Encah/ptus, 

 and Ficns. In the Cretaceous rocks of other paits of Germany 

 the phanerogams are represented by the genera Acer, Salix^ 

 and such conifers as Sequoia and Paiidanns, the screw 

 pine. 



Another very remarkable feature of the Cretaceous flora 

 is its extension, and in great abundance, to the Arctic 

 Regions, where, in North Greenland, are found remains of 

 oak, walnut, plane, laurel, ivy, ilex, and even magnolia and 

 eucalyptus. Again, in the Uppermost Cretaceous of North 

 America, the Laramie formation, one hundred species of 

 •dicotyledons have been discovered, amongst which the vine 

 {Vitis) is especially to be noted. 'J'he Potamac formation 

 of Virginia and Maryland furnishes, besides, about three 

 hundred and fifty species of conifers, cycads, and lower 

 groups, and seventy-five species of angiosperms, including 

 the genera Sassafras, Fiens, Myri<:a, Bomba.v and Aralia. 



The epoch, therefore, during which the Cretaceous rocks 

 were deposited not only Avitnessed the existence of the 

 highest class of animal life, ]\Iammalia, but also saw clothing 

 the earth the highest division, the dicotyledons, of the 

 highest class, the angiosperms, of the highest sub-kingdom 

 of plants, the phanerogams, or in other words the highest 

 .group of plants known to man. 



The stores of mineral treasures in the Secondary rocks, 

 although not so vast and important as those in the Pala30zoic 

 rocks, are yet very great. These rocks contain large amounts 

 of copper and iron ores, and gold has been obtained from 

 the Cretaceous rocks of North America. Alum and gypsum 

 are other substances useful to mankind which these rocks 

 supply, and building stones, both limestones and sandstones, 

 are very largely obtained from Secondary rocks, as well as 

 the more ornamental marbles and alabasters, and various 

 useful sands and clays. Bat their most noteworthy product 

 is perhaps rock-salt, occurring in beds of great thickness and 

 resulting from the drying tip of lakes and shallow seas 

 .usually in Triassic times, but some in the Jurassic epoch. 



In the Tertiaries, the latest of the main subdivisions of 



