REVIEWS 93 



consideration of their origin. He shows that up to the present time 

 the lacustrine theory has been generally accepted, but that recently the 

 difficulties of that theory have been pointed out. The lacustrine 

 origin of the Upper or Loup Fork formation has been rejected by 

 many observers, and now it is generally considered to be as of com- 

 bined lacustrine, fluviatile, flood-plain, and geolian origin. The lower 

 division or White River beds are still regarded by many to be of lacus- 

 trine origin. To these deposits the author turns his attention. 



The lacustrine origin of the White River beds was called seriously 

 in question in 1899 by Dr. W. D. Mathew, of the American Museum 

 of Natural History. W. D. Johnson, also, in the Twenty-first Antiual 

 Report of the United States Geological Survey, regards all of the Ter- 

 tiary deposits of the plains as of fluviatile and flood-plain origin. Mr. 

 Hatcher draws from his wide experience in these beds and presents 

 facts which seem overwhelmingly conclusive in favor of their fluviatile 

 origin as opposed to their lacustrine origin. The physical and palse- 

 ontological evidences combine to fortify his position. The inverti- 

 brate remains were examined by Dall, Pilsbey, and Stanton, who agree 

 that " they belong to species inhabitating swamps and small ponds." 

 Dr. Knowlton reports that the plants are those of "springs, shallow 

 ponds, and brooks," while the author shows that the evidence derived 

 from the vertebrate remains indicates that the lacustrine hypothesis is 

 untenable. 



Mr. Hatcher does not rest with an attempt at destroying the old 

 hypothesis, but presents in its place a rational explanation which satis- 

 factorily accounts for the observed phenomena. He still further 

 strengthens his position by quoting from Mr. H. H. Smith, who 

 describes a region in South America which presents, at the present 

 time, conditions similar to those postulated for the accumulation of 

 the White River deposits. This region exhibits a somewhat remark- 

 able condition of meandering and interlacing streams over a low-lying 

 tract of country which is annually submerged by the floods. The 

 region is comparable in size to the Tertiary deposits discussed, and 

 gives a picture of the possible conditions of our western plains during 

 Oligocene and Miocene times. Seldom do we find an article more 

 replete with valuable and interesting observations. It would seem 

 that those who still entertain a strict lacustrine hypothesis in explana- 

 tion of the White River deposits would do well to strengthen their 

 position in some more substantial manner than has hitherto been done. 



Willis T. Lee. 



