BIBLIOGEAPHY OF NORTH AMERICAN GEOLOGY, 1906-1907. 47 
Clark, William Bullock — Continued. 
481. The Pleistocene fauna [of Maryland], — Maryland Geol. Survey, Pliocene 
and Pleistocene, pp. 139-148, 1906. 
Discusses the value of the fossil contents of the Pleistocene deposits of Maryland for 
correlating the beds with those of other areas. Includes observations and tables show- 
ing the geographic distribution and geologic range of species. 
482. Systematic paleontology of the Pleistocene deposits of Maryland : 
Crustacea, Mollusca, Coelenterata, Protozoa. — Maryland Geol. Survey, Pliocene 
and Pleistocene, pp. 172-210, 213-216, 26 pis., 1906. 
483. The classification adopted by the U. S. Geological Survey for the 
Cretaceous deposits of New Jersey, Delaware, Maryland, and Virginia. — Johns 
Hopkins Univ. Circ, now ser., 1907, no. 7, pp. 1-A [589-592], 1907. 
484. Publications of the Maryland Geological Survey, Maryland State 
Weather Service, and Maryland Forestry Bureau. — Johns Hopkins Univ. Circ., 
new ser., 1907, no. 7, pp. 5-20 [593-608], 1907. 
485. Maryland Geological Survey, Calvert County, Baltimore, 1907. 227 pp., 
14 pis., 11 tigs. With atlas of 3 folded maps. 
486. Maryland Geol. Survey. St. Mary's County, Baltimore, 1907. 209 pp., 
10 pis., 12 tigs. With atlas of 3 folded maps. 
Clark, William Bullock, Hollick, Arthur, and Lucas, Frederic. 
487. The Pliocene and Pleistocene deposits of Maryland: The interpretation 
of the paleontological criteria. — Maryland Geol. Survey, Pliocene and Pleisto- 
cene, pp. 139-152, 1906. 
Clark, William Bullock, and Mathews, Edward B. 
488. Report on the physical features of Maryland, together with an account 
of the exhibits of Maryland mineral resources made by the Maryland Geological 
Survey. — Maryland Geol. Survey (Special Publication, vol. 6, pts. 1 and 2t, 
284 pp., 30 pis., 19 figs., geol. map (in pocket), 1906. 
A general account of the physiography, geology, and mineral resources of the State. 
Clark, William Bullock, and Miller, Benjamin Le Roy. 
489. A brief summary of the geology of the Virginia coastal plain. — Virginia 
Geol. Survey, Geol. Ser., Bull. no. 2. pp. 11-24, 1906. 
(lives a summary of the stratigraphy of the coastal plain in Virginia, embracing for- 
mations of Jurassic (?), Cretaceous, Tertiary, and Quaternary age. 
Clarke, Frank W. 
490. The statistical method in chemical geology. — Am. Philos. Soc, Proc, 
vol. 45, no. 182. pp. 14-32, 1906. Abstract: Science, new ser., vol. 23, pp. 929 
930, June 22. 1906. 
Determines the approximate average chemical composition of the earth's crust and 
discusses the methods employed and the validity of the results obtained. 
491. The composition of the red clay. — Jour. Geology, vol. 15, no. 8, pp. 
783-789, 1907; Roy. Soc. Edinburgh, Proc, vol. 27, pp. 167-171, 1907. 
Clarke, John M. 
492. Nomenclature of the New York geologic formations.— University of 
the Shite of New York, High School Department, Bull. 25, pp. 495 506, Decern 
ber, 1904. 
493. Second report of the director of the science division 1905, Including 
the 59th report of the State .Museum, the 25th report of the state geologist, and 
the report of the state paleontologist 1905 (reprinted from the 59th Annual 
Report of the New York State Museum, vol. 1 ). pp, :. *.»'.». L906, 
