A' A TURE 



257 



Devonian rocks of Xew York, Pennsylvania, and eastern 

 Ohio, as in that region the stratigraphieal succession and 

 the continuity of the rocks were sufficiently clear to enable 

 llie author and his assistants 10 work out the relations 

 between the geological formations and the distribution of 

 life. The term fauna is commonly used in pala-ontology to 

 indicate the list of fossils contained in a single formation, 

 but as the author admits, the limits of formations vary con- 

 siderably in different localities, and do not coincide with 

 the limits of faunas. He introduces the term faunule to 

 distingfuish an aggregate of fossils associated either in a 

 single stratum, or in several contiguous strata that may 

 be many feet in thickness — the aggregate being composed 

 of the same set of species. The fauna, on the other hand, 

 is defined as an aggregate of local and temporary faunules 

 In which is expressed a common, corporate aggregate of 

 species. The faunule is limited to a single set of conditions. 

 1 he fauna is to be discriminated by the dominant species, 

 and it preserves its integrity and identity so long in 

 succession, and so far in distribution, as the dominant 

 species retain their ascendancy among their associates. 

 The marine fauna itself is not the universally distributed 

 marine life of a particular epoch, but the fauna of a par- 

 ticular environment of that epoch. 



The facts recorded by the author show that migration, not 

 of single species, but of the whole fauna has sometimes 

 taken place. There has been transgression of one fauna 

 over another, thus calling for the assumption that the limits 

 of a formation based upon sudden change in the fossil con- 

 tents cannot be regarded as s^'nchronous for two parts of 

 even the same province, and, wherever they are thus sudden 

 and sharp, cannot be synchronous with the limits of either 

 the earlier or later fauna in evidence. The detailed study 

 of the migrations and recurrence of species is of the utmost 

 importance, and in this respect alone we have much to 

 learn. The author rightly remarks that for the practical 

 purposes of geological mapping and the descriptions of 

 geological structure the formations are the essential 

 elements, while his statistics demonstrate the intrinsic value 

 of fossils for measuring and indicating geological time. 

 His obsjrvations show the necessity for a dual nomenclature 

 — stratigraphieal and biological — and they indicate also that 

 '■ At present we know too little about fossil faunas to be 

 able to predict in what manner their actual time limits will 

 be defined or discriminated, but enough light has already 

 been thrown upon the matter to show that it will be by 

 H'eans of the history which organisms have expressed in 

 their continuous life and evolution that we may expect ulti- 

 mately to mark off the stages of geological tiine. " 



■' Notes on the Geology of South-western Idaho and South- 

 eastern Oregon '" are contributed by Mr. Israel C. Russell 

 (BuUetiii No. 217). The notes are the result of a rapid 

 reconnaissance made with the special view of studying the 

 artesian basins ; these comprise large tracts of rich agri- 

 cultural land, throughout which the conditions justify the 

 opinion that flowing water may be obtained. Particular 

 descriptions and illustrations are given of the cinder 

 buttes and craters of the recent, but now extinct, volcanoes. 

 At each of the volcanic centres it seems that the first erup- 

 tions were of the explosive type, and that the elevations 

 then produced by the accumulation of projectiles were to a 

 considerable extent buried by the subsequent quiet effusion 

 of vast quantities of liquid lava (basalt). 



" Descriptive Geology of Nevada South of the Fortieth 

 Parallel and Adjacent Portions of California," by Mr. J. E. 

 Spurr {Biillelin No. 208), contains particulars of a great 

 variety of formations from Archaean to Carboniferous, also 

 of Jura-Trias, Tertiary, and later deposits, as well as of 

 granites, rhyolites, andesites, and other igneous rocks. 

 The work is based on a series of traverses, and is to be re- 

 garded as a preliminary survey, as the topographic map 

 is imperfect ; but the records of facts observed are full of 

 itterest. 



" The Geology of Ascutney Mountain, Vermont," is by 

 Mr. R. A. Daly (Bulletin No. 209). In this work we have 

 the results of an investigation of the lithology and geology- 

 of a plexus of eruptive rocks and of the metamorphic 

 aureole in bordering schistose rocks. The author concludes 

 with hypotheses on the manner of intrusion, on abyssal 

 assimilaticrn, and on the evidences of differentiation of the 

 igneous masses. 



>0. 181 I. ^'M . 70I 



"Stratigraphy and Palaeontology of the L pper Carbon- 

 iferous Rocks of the Kansas Section " is the title of a 

 report by Messrs. G. I. .Adams, G. H. Girty, and David 

 White (Bulletin No. 211). This work summarises the in- 

 formation on the subject, including extensive faunal lists 

 and such data as are available concerning the flora. The 

 plants appear to represent the topmost Carboniferous, if 

 not the so-called permo-Carboniferous, of western Europe. 



Economic geology is dealt with in Bulletins Nos. 212, 213, 

 218, 219, 223, and 225. " The Oil Fields of the Texas- 

 Louisiana Gulf Coastal Plain " are fully described by 

 Messrs. C. W. Hayes and W. Kennedy ; " The Coal Re- 

 sources of the Yukon, Alaska," are discussed by Mr. A. J. 

 Collier, who considers that with proper development there 

 will probably be sufficient coal to supply local demands for 

 some time to come; "The Ore Deposits of Tonopah, 

 Nevada," are reported on briefly by Mr. J. E. Spurr, who 

 points out that the most important mineral veins occur in 

 the early Tertiary andesites, and that the values in the ores 

 are entirely gold and silver; "Gypsum Deposits in the 

 United States," by G. I. Adams and others, are treated 

 with especial reference to economic conditions; and " Con- 

 tributions to Economic Geology," 1902 and 1903, have been 

 prepared by a number of authors under the direction of 

 Messrs. S.F. Emmons and C. W. Hayes; these contribu- 

 tions relate to metalliferous deposits, coal, oil, gas, stone, 

 cements, clays, fuller's earth, gypsum, phosphates, mineral 

 paints, &c. 



In Bulletin No. 220, Mr. F. \V. Clarke has tabulated the 

 " Mineral Analyses from the Laboratories of the L'.S. 

 Geological Survey, 1880 to 1903." 



In Bulletins Nos. 214, 215, 216, 221, 222, 224, and 227, we 

 have a catalogue and index of the publications of the L nited 

 States Geological Survey, igoi to 1903 ; bibliography and 

 index of North American geology for 1902 ; catalogue and 

 index of the publications of the Hayden, King, Powell, and 

 Wheeler surveys ; results of primary triangulation ; geo- 

 graphic tables and formulas; gazetteer of Texas, edit. 2; 

 and " The United States Geological Survev, its Origin, 

 Development, Organisation, and Operations." 



II. Monographs. 



Monograph No. 44 contains the last work of Prof. 

 Alpheus Hyatt, the " Pseudoceratites of the Cretaceous"; 

 this was almost ready for the printer at the time of his 

 death in January, i9'o2, and it has been edited by Mr. 

 T. \V. Stanton. It is illustrated by 47 plates, and these, 

 together with the descriptions of species and the reference 

 of these and other species to new genera of Ammonoidea. 

 were arranged or selected by the author. As the editor 

 remarks, "The multiplication of families, genera, and 

 species will be understood by all who are acquainted with 

 Professor Hyatt's habit of attempting to express in the 

 terminology every important fact observed in the course 

 of his investigations." In some cases the classification 

 of the forms is incomplete, as the author's opinions on 

 certain questions had evidently become much modified since 

 his previous publications. The Pseudoceratites he speaks 

 of as "an artificial group, including for convenience of 

 treatment all the retrogressive genera of the Cretacic that 

 have sutures with simple outlines resembling those of 

 Triassic cephalopods, formerly included under the name 

 Ceratites." Among the British forms referred 10 is 

 /Inimoiiitcs (Mantelliceras) Mantelli, of Sowerby. 



Monograph No. 45 is on " The Vermilion Iron-bearing 

 District of Minnesota," by Mr. J. Morgan Clements, and it 

 is accompanied by a folio atlas of geological,^ mining, and 

 topographic maps. This great iron-bearing district has an 

 area of, approximately, 1000 square miles in north-eastern 

 Minnesota, and it resembles the other iron-bearing districts 

 of the Lake Superior region in that the rocks are of great 

 geological antiquity. Iron ore was first noticed in the 

 district in 1850, but its economic importance was not 

 realised until long subsequently. The ores occur in four 

 areas, one of which includes the Giant's Range, which 

 attains a height of 2120 feet above sea-level. The rocks 

 comprise Archa;an, divided in ascending order into the Ely 

 greenstone, the iron-bearing Soudan formation, and various 

 granites. The greenstones, though highly altered, are 

 largely of volcanic character, but with them are associated 



