viii - CONTENTS TO VOLUME XXII 



PAGE 



A Comparison of the Cambrian and Ordovician Ripple-Marks 



Found at Ottawa, Canada. E. M. Kindle 703 



New and Little-known Insects prom the Miocene of Florissant, 



Colorado. T. D. A. Cockerell 714 



Petrological z\bstracts and Reviews 725 



NUMBER VIII 



The Strength of the Earth's Crust. VII. Variation of 

 Strength with Depth as Shown by the Nature of Depar- 

 tures FROM IsosTASY (Scction A). Joseph Barrell . . . 729 

 The Analcite Basalts of Sardinia. H. S. Washington . . . 742 

 On the Conditions under Which the Vegetable Matter of the 



Illinois Coal Beds Accumulated. T. E. Savage . . 754 



Berea Sandstone in Eroded Cleveland Shale. Wilbur Greeley 



Burroughs 766 



The Average Igneous Rock. W. J. Mead 772 



Eocene Horizons of California. Clarence A. Waring . . . 782 

 Contemporaneous Deformation: A Criterion for Aqueo-glaclal 



Sedimentation. Frederic H. Lahee 786 



Problems of Petrographic Classification Suggested by the 



"Kodurite Series" of India. Whitman Cross .... 791 

 A Phenomenon of the Kansan Drift in Nebraska. Erwin H. 



Barbour 807 



Eduard Suess. WiUiam Herbert Hobbs 811 



Reviews 818 



Recent Publications 819 



Index to Volume XXII 825 



