608 PROCEEDINGS O* THE BALTIMORE MEETING 



Page 

 Criteria for discrimination of the age of glacial drift sheets as modi- 

 fied by topographic situation and drainage relations [abstract] ; by- 

 William C. Alden 638 



Lake Ojibwa, last of the great glacial lakes [abstract] ; by A. P. 



Coleman 639 



Glacial erosion on Kelleys island, Ohio ; by Frank Carney 640 



Chalk formations of northeast Texas [abstract] ; by C. H. Gordon 645 



Results of a recent investigation of the Coastal Plain formations in the 

 area between Massachusetts and North Carolina [abstract] ; by Wil- 

 liam Bullock Clark 646 



Geologic relations of the Cretaceous floras of Virginia and North Caro- 

 lina [abstract] ; by Edward W. Berry 655 



Report of Committee on earthquake and volcanic observations 659 



Use of "ophitic" and related terms in petrography ; by A. N. Winchell. 661 

 Chemical composition as a criterion in identifying metamorphosed sedi- 

 ments [abstract] ; by Edson S. Bastin 667 



Tertiary drainage problems of eastern North America [abstract] ; by 



Amadeus W. Grabau 668 



Drainage evolution in central New York [abstract] ; by H. L. Fair- 

 child 668 



Nantucket shorelines, IV [abstract] ; by F. P. Gulliver 670 



Iron ores of Maryland [abstract] ; by Joseph T. Singewald, Jr 671 



Quartz as a geologic thermometer [abstract] ; by Fred E. Wright and 



E. S. Larsen 671 



Session of Thursday, December 31 672 



Occurrence of the Magothy formation on the Atlantic islands [ab- 

 stract] ; by Arthur Barneveld Bibbins 672 



Erosion intervals in the Tertiary of North Carolina and Virginia; by 



Benjamin L. Miller 673 



Character and structural relations of the limestones of the Piedmont 

 in Maryland and Virginia [abstract] ; by Edward B. Mathews and 



J. S. Grasty 678 



Recurrence of the Tropidoleptus fauna in the Chemung of Maryland ; 



by Charles K. Swartz 679 



Geological distribution of the Mesozoic and Cenozoic Echinodermata of 

 the United States [abstract] ; by W. B. Clark and M. W. Twitchell. . 686 



Age of the Gaspe sandstone ; by Henry Shaler Williams 688 



Brachiopoda of the Richmond group [abstract] ; by August F. Foerste. 699 

 Reconnaissance in Arizona and western New Mexico along the Santa 



Fe railroad [abstract] ; by N. H. Darton 700 



Geologic studies in the Alaska peninsula [abstract] ; by Wallace W. 



Atwood TOO 



Some features of the Wisconsin Middle Devonic [abstract] ; by H. F. 



Cleland T01 



Ice-borne boulder deposits in mid-Carboniferous marine shales [ab- 

 stract] ; by Joseph A. Taff 701 



