BIBLIOGRAPHY <^>31) 



Theodore Fuchs : Ueber die Natur von D?emonelix, Barbour. Annalen k. k. 

 Naturh. Hofmuseums, Wien, 1893, pages 91-94. 



James H. Gardner : The physical origin of certain concretions. Journal of 

 Geology, volume XVI, number 5, 1908, pages 452-458. 



Sir Archibald Geikie : Class-book of Geology, 1893, pages 127, 136, 140-142, 

 156, 177, 178, figures 64, 65. 

 Text-book of Geology, third edition, pages 66, 103, 510, 513, 1053 ; Analysis 

 of clay ironstones, 1893, page 147, figure 26. 



James Geikie : Structural and Field Geology. Edinburgh, 1912, page 121. 



E. Geinitz : Kolloiderscheinungen in Konkretionen. Centralbl. f. Min., 1912, 

 pages 282-287 and figures. 



J. G. GooDCHiLD : Guide to the collection of Scottish agates. Edinburgh Mu- 

 seum of Science and Art, 1899. 



L. P. Gratacap : Opinions on claystones and concretions. American Natural- 

 ist, volume XVIII, 1884, pages 882-892, 2 plates. 



Alex. H. Green: Manual of (ieology (3), 1882, pages 279-282, figure 105. 

 (Figure of concretions w^ith lines of stratification running through 

 them.) 



W. S. Gresley : Notes on "Cone-in-cone" structure. Geological Magazine, 

 Decade III, volume IV, 1887, pages 17-22. 

 Cone-in-cone. Geological Magazine, London, volume IV, 1907, page 575. 



C. W. Gpmbel: Bildung von Oolite. Neues Jahrbuch fur Min. Geol. und 

 Paleon., 1873, page 303. 



James Hall: Natural History of New York, part 4, 1843, page 192. 



Hall and "Whitney : Clay concretions, Muscatine County, Geology of Iowa, 

 volume 1, part 1, 1858, pages 275, 276, figures 38, 39. 



Erasmus Haworth : Section at Fort Scott showing calcareous concretions in 

 the shale adjacent to Fort Scott coal. The University Geological 

 Survey of Kansas, 1896, volume 1, page 88, figure 4. 



Charles W. Hayes : Growth of concretions of different composition under a 

 variety of conditions. Science (abstract), new series, volume 33, 

 April 7, 1911, page 550. 



A. L. Herrera : Estructuras organoideas en una variedad de opalo, la menilita, 

 estudio acerca de las oolitas (organic structure in menilite and the 

 origin of oolite). Mexico, Secretaria de Fomento. . . . Direction 

 de Estudios Biologicos, BoL, t. i, 1916, pages 367-375. 



Eugene W. Hilgard : On the Geology of Lower Louisiana. Smithsonian Con- 

 tributions, volume XXIII, article III, number 248, 1881, pages 11, 12 

 (accepted for publication October, 1871). 



W^iLLiAM Hill : Flint and chert. Proceedings of the Geological Association, 

 ■ volume XXII, 1911, pages 93 94. 



Edward Hitchcock: A sketch of Geology, etc., of the Connecticut River. 

 American Journal of Science, volume VI, part 2, 1823, page 229. 

 Report on the Geology of Massachusetts, 1835, pages 186, 187. 

 Sketch of the Geology of Portland and its vicinity. Boston Journal of 



Natural History, volume 1, 1834-1837, pages 325-331. 

 Final report on the Geology of Massachusetts. Analysis; page 96 ; Con- 

 cretions, 1841, pages 406-418. 

 Elementary Geology, thirtieth edition, 1857, pages 24, 25, figures 4-8. 



