MOOK, STUDY OF THE MORRISON FORMATION 179 



1896. 8. Marsh, O. C : "The Jurassic formation on ttie Atlantic Coast." 

 Amer. Journ. Sci., 4th ser., vol. ii. pp. 433-447, 2 figs., 1896. [Description 

 of the Baptanodon and Atlantosaurus beds of the west. Description of 

 the Pleuroccelus beds and the Potomac formation. Discussion of the rela- 

 tive importance of fossils, the age of the Wealden and the position and 

 character of the Jurassic] 



1896. 9. Gilbert, G. K. : "Age of the Potomac formation." Sci., N. S., vol. 

 iv, pp. 875-877, 1896. [Discusses the methods of correlation used by Marsh 

 in his paper on the Jurassic formation of the Atlantic Coast. Slightly 

 favors Cretaceous age for the Potomac beds.] 



1896. 10. Hill, R. T. : "A question of classification." Sci., N. S., vol. iv, pp. 

 918-922, 1896. [Equivalents of the Potomac extend along the Atlantic 

 Coast and westward into Texas. Tuscaloosa equals Lower Trinity. The 

 whole is Cretaceous. Discussion of Marsh's evidence of the Jurassic age 

 of these beds.] 



1896. 11. Marcou, Jules: "The Jura in the United States." Sci., N. S., 

 vol. iv, pp. 94.5-947, 1896. [Potomac formation Jurassic in age.] 



1897. 1. Haworth, Erasmus : "Underground waters of southwestern Kan- 

 sas." U. S. Geol. Surv., Water Supply Paper, No. 6, 63 pp., 12 pis., 2 figs., 

 1897. [Map and discussion of Jura-Trias beds. Red beds were deposited 

 in ocean water.] 



1897. 2, Gilbert, G. K. : "Pueblo, Colorado, quadrangle." U. S. Geol. Surv., 

 Geol. Atlas, Folio No. 36, 7 pp., 16 figs., 6 maps, section sheet, illustration 

 sheet. 1897. [Discussion and sections of Mesozoic strata, including the 

 Morrison.] 



1897. 3. Clark. Wm. B. : "Outline of present knowledge of the physical fea- 

 tures of Maryland, embracing an account of the physiography,, geology 

 and mineral resources." Md. Geol. Surv., vol. i, pp. 141-228, pis. 6-13, 1897. 

 [Upper Jurassic and Lower Cretaceous deposited in brackish water.] 



1897. 4. Clark, ■ Wm. B., and Bibbins, Arthur : "The stratigraphy of the 

 Potomac group in Maryland." Journ. Geol., vol. v, pp. 479-506, 1897. [De- 

 scriptions of the Patuxent, Arundel, Patapsco and Raritan formations. 

 Discussions of the relations and age of the deposits and the views of other 

 writers. Patuxent and Arundel are Jurassic? Patapsco is Lower Creta- 

 ceous. The whole series deposited in brackish water.] 



1897. 5. Scott, Wm. B. : An introduction to geology. 1st ed., xii -j- 573 pp., 

 169 figs., 13 pis., Macmillan Co., 1897. [Name "Como" given to the Morri- 

 son in southern Wyoming. The formation is assigned to the Lower Cre- 

 taceous period.] 



1898. 1. Purington, C. W. : "Preliminary report on the mining industry of 

 the Telluride quadrangle, Colorado." U. S. Geol. Surv., 18th Ann. Rep., 

 pt. 3, pp. 751-848, pis. 103-158, figs. 66-74, 1898. [Notes on the La Plata 

 and Gunnison formations.] 



1898, 2. Spurr, J. E. : "Geology of the Aspen mining district, Colorado, with 

 atlas." U. S. Geol. Surv., Monograph, No. 31, 260 pp., 43 pis., 11 figs., .30 

 atlas sheets, 1898. [Description of the Gunnison formation, part of which 

 is correlated with the Atlantosaurus beds.] 



1898. 3. Marsh, O. C. : "Jurassic formation on the Atlantic Coast." Sup- 

 plement. Amer. Journ. Sci., 4th ser., vol. vi, pp. 105-115, 1 fig. 1898. [Re- 



