Revieics — Geological Suri-ey U.S. Water- Siipjjly Reports. 137 



and the number of forms now known from the Raritan formation = 

 Amboy Clays is between 160 and 170. The ferns are particularly 

 interesting and varied, several being referred to the genera Gleichenia, 

 Diclcsonia, Asplenium, and Ophioglosswn. The Cycads are represented 

 by numerous members of the genus Podozamites, and a species of 

 Microzamia. The Coniferae are referred to the genera Dammara, 

 Brachyphyllum, Thuja, Sequoia, and Widdrinytonites among others. 

 The Ginkgoales are represented by Baiera and Czelcanowskia. Only 

 a single Monocotyledon is recorded, but the Dicotyledons, as is 

 invariably the case in Upper Cretaceous floras, are both very numerous 

 and very varied, and far outnumber tiie representatives of all other 

 groups. Among the Dicotyledonous leaf-impressions figured are good 

 examples of the leaves of Ilaynolia, Liriodendron, and Sassafras, as 

 well as those of Salix and Populus. A general account of the Earitan 

 formation and its correlation is added, and the distribution of the 

 species desci'ibed, in time and space, is also adequately considered. 

 On the whole the memoir appears to be a sound piece of work, note- 

 worthy in that the author has obviously rejected as unsatisfactory the 

 less perfect specimens in the collections which he describes, and he 

 has thus avoided the common error of making much of material which 

 is often quite unworthy of description. 



E. A. N. A. 



IV. GrEOLOGICAL SuKVEY OP THE UnITED StATES. 



WATER-SUPPLY Papers Nos. 263, 266, 267, and 268 (1911) 

 contain accounts of the surface water in the basins of the Ohio, 

 Missouri, Lower Mississippi, and in the western Gulf of Mexico. 

 In the introductory portions of these memoirs there are useful 

 definitions of terms used in hydraulic computations; descriptions of 

 the methods of measuring stream-flow, with illustrations ; descriptions 

 of the river basins, with details of gaugings ; and illustrations of 

 rivers, waterfalls, canals, wasteway gates, dams, and headworks. 



"Water-Supply Paper JSTo. 273 (1911) is on the Quality of the 

 Water Supplies of Kansas, by Mr. H. N. Parker, with report on 

 stream pollution through mine-waters, by Mr. E. H. S. Bailey. 

 No. 275 (1911) is on the Geology and Water Resources of Estancia 

 Valley, New Mexico, by Mr. 0. E. Meinzer. The physiography 

 and geology of the district are described ; there are accounts of wind- 

 deposited clay, of alkali and other soils, and of methods of irrigation. 

 The subjects are illustrated by maps and photographic views. 



No. 276 (1911) contains an account of the Geology and Underground 

 Waters of North-Eastern Texas, by Mr. C. H. Gordon, with illustrations 

 and geological map. 



No. 277 (1911), on Ground Water in Juab, Millard, and Iron 

 Counties, Utah, by Mr. 0. E. Meinzer, contains much interesting 

 information on physiography and geology, on the soils and vegetation, 

 on the relation of rainfall to dry-farming, on the ground and artesian 

 water in igneous and sedimentary rocks, in lakes and valleys, and on 

 desert flats. Springs, hot and cold, and irrigation are dealt with, and 

 there are many illustrative maps and diagrams. 



