180 ANNALS NEW YORK ACADEMY OF SCIENCES 



ply to Gilbert's criticism and restatement of evidence for Jurassic age of 

 the Potomac beds.] 



1898. 4. Todd, James E. : "Section along Rapid Creek from Rapid city west- 

 ward. South Dak. Geol. Surv., Bull., No. 2, pp. 27-40, pis. 2-5, 1898. 

 [Notes on the Blaciv Hills Jurassic] 



1898. 5. Marsh, O. C. : "Cycad horizons in the Rocky Mountains." Amer. 

 Journ. Sci., 4th ser., vol. vi, p. 197, 1898. [Notes on the Mesozoic strata 

 of the Black Hills.] 



1898. 6. Davis, W. M. : "Physical geography," xviii + 432 pp., 9 pis., 261 

 figs., frontsp., Ginn & Co., N. Y., 1898. [Discussion of river deposits. De- 

 scription of the Hoangho alluvial plain.] 



1899. 1. Marsh, O. C. : "Footprints of Jurassic dinosaurs." Amer. Journ. 

 Sci., 4th ser., vol. vii, pp. 229-232, 3 figs., 1899. [Footprints found in the 

 Morrison of the Black Hills region.] 



1899. 2. Darton, N. H. : "Jurassic formations of the Black Hills of South 

 Dakota." Geol. Soc. Amer. Bull., vol. x, pp. 38.3-396, 3 pis., 1899. [De- 

 scription and history of the Black Hills Jurassic beds. Beulah shales 

 equivalent to the Morrison.] 



1899. 3. Cross, Whitman : "Telluride, Colorado, quadrangle." U. S. Geol. 

 Surv., Geol. Atlas, Folio No. 57, 18 pp., 4 maps, section sheet, 3 illustra- 

 tion sheets, 1899. [Sections and descriptions of the La Plata and McElmo 

 formations. These names are proposed for divisions of the Gunnison for- 

 mation.] 



1899. 4. Cross, Whitman, Spencer, A. C, and Purington, C. W. : "La Plata, 

 Colorado, quadrangle." U. S. Geol. Surv., Geol. Atlas, Folio No. 60, 14 pp., 

 4 maps, 2 illustration sheets, 1899. [La Plata and McElmo formations 

 described and discussed.] 



1900. 1. Knight, W. C. : "The Wyoming fossil fields expedition of July, 

 1899." Nat. Geog. Mag., vol. xi, pp. 449-465, 8 pis., 1900. [Description of 

 Como Bluff and other Morrison localities.] 



1900. 2, Knight, W. O. : "Jurassic rocks of southeastern Wyoming." Geol. 

 Soc. x\mer.. Bull., vol. xi, pp. 377-388, pi. 23, 1900. [Detailed sections, 

 map, descriptions and faunal lists.] 



1900. 3. Knight. W. C. : "A preliminary report on the artesian basins of 

 Wyoming." Wyo. Exp. Station, Bull. No. 45, pp. 107-251, 14 pis., 15 figs., 

 map, June, 1900. [Brief description of the Morrison formation.] 



1900. 4. Cross, Whitman, and Spencer, A. 0. : "Geology of the Rico Moun- 

 tains, Colorado." U. S. Geol. Surv., 21st Ann. Rep., pt. 2, pp. 15-165. pis. 

 1-22, 1900. [The La Plata is correlated with the lower part of the Gunni- 

 son, and the McElmo with the upper part, and in part with the Morrison.] 



1900. 5. Logan, W. N. : "The stratigraphy and invertebrate faunas of the 

 Jurassic formation in the Freezeout Hills of Wyoming." Kans. Univ. 

 Quart., vol. ix, pp. 109-134, pis. 25-31, 5 figs., 1900. [Descriptions, detailed 

 section and descriptions of new species of invei'tebrate fossils.] 



1900. 6. Ward, L. F. : "Description of a new genus and twenty new species 

 of fossil cycadean trunks from the Jurassic of Wyoming." Wash. Acad. 

 Sci., Proc, vol. i, pp. 251-300, pis. 14-21, 1900. [Stratigraphic notes and 

 descriptions of the cycads. which form the principal element of the Mor- 

 rison flora.] 



