Geology and Natural History. 517 



illustrations in the text. Minneapolis, 1891. — This volume treats, 

 as the title-page further states, of the geology, discovery, devel- 

 opment, qualities and origin of the ores, and of comparison with 

 those of other iron districts. The rocks are described with some 

 detail, colored microsco]3ic sections given of several of them, and 

 the age of the deposits is discussed at length. One of the inter- 

 esting plates of the volume represents the famous Greenland mass 

 of iron found embedded in basalt and weighing 19 tons, now in 

 the museum of the Royal Academy at Stockholm. 



4. The Tertiary Insects of North America ; by Samuel H. 

 Scudder, IT. S. Geol. Surv. of the Territories, F. V. Hayden. 

 Vol. xiii, pp. 734, Plates I-XXVIII. Washington, 1890.— This 

 volume brings the subject of fossil Tertiary insects into promi- 

 nence as a department of American paleontology. Formerly, it 

 was impossible to make any general comparison between the 

 American and European faunas, as the former was meager both 

 in specimens and species. Owing to the rapid geological explora- 

 tion of the West, and to the labors of the author ol this mono- 

 graph, the lack of material and of definite knowledge have both 

 been removed. Moreover, as the insect-bearing rocks are so ex- 

 tensive, and have been investigated at so few localities, it is 

 evident that further researches will result in a richer and more 

 varied fauna than has yet been developed elsewhere. 



Six hundred and twelve species are described, divided among 

 the orders as follows: Myriapoda 1, Arachnida 34, Neuroptera 

 66, Orthoptera 30, Hemiptera 266, Coleoptera 112, Diptera 79 

 Lepidoptera 1, and Hymenoptera 23. By far the most abundant 

 fauna occurs in the Tertiary lake basin at Florissant, Colorado. 

 Some of the higher orders of insects are more fully represented 

 than is indicated in the enumeration of species. Their descrip- 

 tion is reserved for the acquisition of more and better material. 

 Other localities yielding fossil insects and included in the volume 

 are: Green river, Fossil and Horse Creek, Wyoming; the vicinity 

 of Quesnel, British Columbia ; Scarboro, Ontario ; and Port 

 Kennedy, Pennsylvania. c. e. b. 



5. Trilohites of the Upper Carboniferous of Kansas. — The 

 Kansas City Scientist — a popular scientific monthly of 16 pages 

 8vo, made the official organ of the Kansas City Academy of 

 Science — contains, in its March number, an article by S. G. Hare 

 on species of Phillipsia, illustrated by a plate ; and the February 

 number contains an account of foot-prints from the Upper Carbo- 

 niferous, by E. Butts. 



6. An Introduction to the study of Petrology : The Igneous 

 Mocks; by Frederick H. Hatch. 128 pp. London and New 

 York, 1891 (Swan Sonnenschein & Co. ; Macmillan & Co.) This 

 little book will be found useful by those desiring a concise 

 account of the minerals which are present in the various types of 

 igneous rocks and of the composition and occurrence of these rocks 

 themselves. The space is about equally divided between these 

 two parts, and the descriptions are probably as satisfactory as is 

 possible where the subjects are treated with such brevity. 



