MARyi>A?\D GEOLOGICAL SURVEY 45 



ISGO. 8vo, 145 pp. Maps. Appendix. Mineral Kesonrces of Mary- 

 land, 20 pp. Annapolis, 18G0. 



The report is accompanied by a colored geological map which shows the 

 distribution of the various formations. The Coastal Plain formations repi-e- 

 sented are the Cretaceous, Tertiary, and Post Tertiary, while the iron-ore 

 clays of the Cretaceous are separated from the other Cretaceous deposits. A 

 brief description is given of each formation. 



The green sand and shell marl deposits are mentioned. The Cretaceous 

 clays of the county are briefly described. The carbonate of iron ores of the 

 Cretaceous are described and also deposits of iron pyrites near Oxon Creek. 



1861. 



Johnston^ Christopher. Upon a Diatomaceous Eartli from 

 Xottingham, Calvert Co., Maryland. 



Proc. Amer. Assoc. Adv. Sci., vol. xiv, 1860, pp. 159-161. 



The writer gives reasons for believing that the "Bermuda earth" must 

 have come from Nottingham. A brief description of the deposit is given. 

 Tyson is quoted as being unable to decide whether the bed belongs to the 

 Upper Eocene or the Lower Miocene. 



^ORMAN^ George. On some Undescribed Species of Diatomaceae. 

 (Read Nov. 14, 1860.) 



Trans. Micros. Soc, London, n. s. vol. ix, 1861, pp. 5-9. 



Describes and figures Aulacodiscus sollitianus (n. sp.) from Nottingham, 

 Md. 



1862. 

 Tysox, Philip T. Second Report of Philip T. Tyson, State Agri- 

 cultural Chemist, to the House of Delegates of Maryland, January, 

 1862. 8vo, 92 pp. Annapolis, 1862. 



Among the mineral resources described are the following from this county: 

 Carbonate of iron ores supposed to belong to the oolitic period, a large de- 

 posit of iron pyrites at Oxen Creek, five miles south of Washington, clays, 

 and tripoli near Nottingham. 



1864. 

 Conrad^ T. A. ISTotes on Shells, with description of new fossil 

 Genera and Species. 

 Proc. Acad. Nat. Sci., Phila., vol. xvi, 1864, pp. 211-214. 



Dosmiopsis meekil is reported from a locality six miles east of Washing- 

 ton where it is said to occur "abundantly in a dark grey quartzose sand." 

 It is said to characterize the oldest portion of the American Eocene which 

 has yet been observed, p. 213. 



