Geology and Mineralogy . 397 



II. Geology and Mineralogy. 



1. Recent Publications of the XT. S. Geological Survey. — The 

 following volumes have been recently issued by the U. S. 

 Geological Survey, Parts II, III, IV, V, VII of the Twentieth 

 Annual Report. (See also this Journal, ix, p. 447.) 



Part II. General Geology and Paleontology. Pp. 1-953, plates 

 i to cxciii. This volume includes six papers, as follows : G. F. 

 Becker, Brief memorandum on the Geology of the Philippine 

 Islands, pp. 1-8 ; T. N. Dale, A study of Bird Mountain, Ver- 

 mont, pp. 9-24, pi. i, ii ; G. H. Girty, The fauna of the Ouray 

 formation, pp. 25-82, pi. iii-vii ; I. C. Russell, preliminary paper 

 on the geology of the Cascade Mountains in northern Washing- 

 ton, pp. 83-210, pi. viii-xx; L. F. Ward, Status of the Mesozoic 

 floras of the United States, pp. 211-748, pi. xxi-clxxix; David 

 White, Stratigraphic succession of the fossil floras of the Potts- 

 ville formation in the southern anthracite coal field, Pennsylvania, 

 pp. 749-918, pi. clxxx-cxciii. 



Of these papers that by Prof. Ward was noticed at length in 

 the last number of this Journal (p. 320). The paper by Prof. 

 Pussell is largely devoted to the glacial and post-glacial geology 

 of the northern and eastern parts of the State of Washington. 

 It is shown that during these times the valleys were filled with 

 gravel and sand to a depth in general of several hundred feet. 

 Subsequently the streams excavated channels through these 

 deposits and in many instances removed them entirely. The 

 portions of the gravel deposits which remain form terraces along 

 the streams, some of which are a mile or more broad and have a 

 down-stream gradient. The terraces occur even in mountain 

 gorges and along torrential streams and in such cases have a con- 

 spicuous down-stream slope — not due to a tilting of the land — 

 which is less steep than the gradient of the present streams. No 

 evidence is found of a modern depression of the land of such a 

 nature as to admit of the flooding of the valleys by the waters of 

 the ocean. The prevalence of glaciers at this time shows a much 

 colder climate and a greater amount of precipitation than at 

 present. 



Part III. Precious-metal Mining Districts. Pp. 1-595, plates 

 i-lxxvii. This volume will be noticed later. It contains three 

 papers : J. S. Diller and F. H. Knowlton, On the Bohemia min- 

 ing region of western Oregon ; W. Linclgren, On the gold and 

 silver veins of Silver City, De Lamar and other mining districts in 

 Idaho; W. H. Weed and L. V. Pirsson, On the Geology of the 

 Little Belt Mountains, Montana. 



Part IV. Hydrography. Pp. 1-660, plates i-lxiii. This 

 volume contains the report of progress on stream measurements 

 for the calendar year 1898 by F. H. Newall, pp. 1-562 ; also an 

 account of the hydrography of Nicaragua by A. P. Davis, pp. 

 563-638. The very rapid development of this new department 



