Maryland Geological Survey 47 



1897 

 Clark, Wm. Bullock, and Bibbins, Arthur. The stratigraphy of 

 the Potomac group in Maryland. 

 Jour. Geol., vol. v, 1897, pp. 497-506. 



, Bagg, B. M., and Shattuck, G. B. Upper Cretaceous Forma- 

 tions of New Jersey, Delaware, and Maryland. 



Bull. Geol. Soc. Amer., vol. viii, 1897, pp. 315-358, pis. xl-1. 



Ward, Lester. Professor Fontaine and Doctor Newberry on the age 

 of the Potomac formation. 



Science, n. s., vol. v, 1897, pp. 411-423. 



1898 

 Knowlton, F. H. A Catalogue of the Cretaceous and Tertiary plants 

 of North America. 



Bull. U. S. Geol. Surv., No. 152, 1898, 152 pp. 



1902 



Berry, Edward W. Notes on Sassafras. 

 Bot. Gaz., vol. xxxiv, 1902, pp. 426-450. 



. Aralia in American Paleobotany. 



Bot. Gaz., vol. xxxvi, 1903, pp. 421-428. 



. The American Species referred to Thinnfeldia. 



Bull. Torrey Bot. Club, vol. xxx, 1903, pp. 438-445. 



Bonsteel, J. A. Soil Survey of Prince George's County, Md. 

 Field Oper. Bureau Soils, 1901, U. S. Dept. Agri., Third Rept. 

 Bureau of Soils, 1902, pp. 173-210, pis. xxi-xxv, with map. 



Dorsey, C. W., and Bonsteel, J. A. The Soils of Cecil County. 

 Md. Geol. Survey, Cecil County, 1902, pp. 227-248, pis. xx-xxii, with map. 



Clark, Wm. Bullock, and Bibbins, A. Geology of the Potomac 

 group in the middle Atlantic Slope. 



Bull. Geol. Soc. Amer., vol. xiii, 1902, pp. 187-214, pis. xxii-xxviii. 



Ries, H. Report on the Clays of Maryland. 



Md. Geol. Survey, vol. iv, 1902, pp. 205-505, pis. xix-lxix. 



Shattuck, G. B., and others. The Physical Features of Cecil County. 

 Md. Geol. Survey, Rept. on Cecil Co., 1902, 322 pp., 30 pis., 24 figs. 



