Sayles — Dilemma of Paleoclimatolo gists. 473 



Note: Since writing this paper Dr. Knowlton has published 

 a reply to the papers of Coleman and Schuchert, but it is not 

 possible to discuss it here. 



22 Abbot, C. G. $ Fowle, F; E., Volcanoes and Climate. Smithsonian Misc. 

 Coll., vol. 60, No. 29, pp. 1-24, 1913. 



1 Atwood, W. W '., Eocene Glacial Deposits in Southwestern Colorado, 

 U. S. G. S., Prof. Paper 95-B, 1915. 



^Barrell, Joseph, Bull. Geol. Soc. America, vol. 27, pp. 112-113/1915. 



24 Blackw elder, Eliot, The Climatic History of Alaska from a New View- 

 point, Trans. 111. Acad. Sci., vol. 10. 



3 Coleman, A. P., Paleobotany and Earth's Early History, this Journal, 

 (5), vol. 1, pp. 315-319, April, 1921. 



20 Croll, James, Climate and Time, 1st Ed., 1875, pp. 433-434. 



™ Barton, N. H., Geothermal Data of the U. S., U. S. G. S., Bull. 701, 

 1920. 



14 David and Siissmilch, Proc. Eoy. Soc, New South Wales, 53, 270, 

 3 919-20. 



9 Be Geer, Baron Gerard, A Geochronology of the last 12,000 years, 

 Compte Eendu Cong. Geol. internat. sess. 11, 1910-1912, pp. 241-253, 2 pis. 



7 Gale, Hoyt S., The Potash Deposits of Alsace, U. S. G. S., Bull. 715-B, 

 pp. 47-48, 1920. 



G Goldring, Winifred, Annual Eings of Growth in Carboniferous Wood; 

 Botanical Gazette, vol. 72, No. 5, Nov., 1921. 



13 Halle, Tliore G., On the Geological Structure of the Falkland Islands; 

 Bull. Geol. Inst. Univ. Upsala, vol. 11, pp. 159-160, 1911. 



22 Humphreys, W. J., Physics of the Air, pp. 569-603, 1920. Volcanic Dust 

 as a factor in the production of climatic changes. Wash. Acad. Sci. Jour., 

 vol. 3, pp. 365-71, 1913. 



17 Joly, John, Eadioaetivity and Geology, 1909, pp. 35-69. 



23 Kirlc, Edwin, Paleozoic Glaciation in Southeastern Alaska. Bull. Geol. 

 Soc. America, vol. 29, No. 1, March, 1918, pp. 149-150. 



2 Knowlton, F. H., Evolution of Geologic Climates, Bull. Geol. Soc. Amer- 

 ica, vol. 30, pp. 499-565, 1919. 



18 Lane, A. C, Michigan Geol. & Biological Survey, Keweenaw Series of 

 Michigan, Chap. VI, p. 757, 1909; pub. 1911. 



3 Hanson, M., Geologic and Present Climates, 1919, p. 217. Also Evolu- 

 tion of Climates. 



* 6 Murray, Sir John, Depths of the Ocean, 1912, pp. 61-62; pp. 160, 166, 

 radium; pp. 221-222; 229-230, water heating. 



10 Sayles, B. W '., Bull. Geol. Soc. America, vol. 27, pp. 110-111, 1915. Proc. 

 Nat. Acad. Sci., vol. 2, pp. 167-170, 1916. Seasonal Deposition in Aqueo- 

 gla.cial Sediments, Mem. Mus. Comp. Zool., Harvard, vol. 47, No. 1, 1919, 



4 Schuchert, C, Evolution of Geologic Climates; this Journal, (5), vol. 1, 

 pp. -320-324, 1921. Also, Climates of Geologic Time; Carnegie Inst, of 

 Wash., Pub. No. 192, pp. 263-298. 



21 Scott, W. B., An Introduction to Geology, 2d ed., 1909, p. 767. 



12 Sederholm, J. J., Subdivision of the Pre-Cambrian of Fenno-Scandia. 

 Compte Eendu Cong. Geol., 11, p. 683-698, 1910-1912. 



15 Shaw, E. W., U. S. G. S. Prof. Paper 85-B, p. 17, 1917. The Mud Lumps 

 at the Mouths of the Mississippi. 



8 Shimer, H. W '., Bull. Geol. Soc. America, vol. 30, No. 4, p. 480. 



Am. Jour. Sci. — Fifth Series, Vol. Ill, No. 18. — June, 1922. 



