82 Forty-second Annual Report on tee 



39. * Keniarks on the Trilobite of the Potsdam Sandstone, named by 



Dr. Owen, Dikellocephalus, and its Relatkms to Asaphus and 

 Ogygia. Ibid., p. 301. 



40. *Kemarks upon the Fossils of the Potsdam Sandstone. Ibid., 



p. 304. 



41. Notice of a Geological Map of the United States and the British 



Provinces of North America, with Explanatory Text, Geological 

 Sections and Plates of the Fossils which characterize the form- 

 ations, by J. Marcou. Am. Jour. Sci., 2d Ser., vol. 17, pp. 199- 

 206. New Haven, 1854. 8vo. 



42. Rapport sur ]a Partie Geologique de I mposition de New York. 



C. Lyell and J. Hall. Traduit par M. A. Langel. Ann ales des 

 Mines, vol. VI, pp. 1-85. Paris, 1854. 8vo. 



43. Report on Coal Lands in Kentucky, for the Kentucky Mining and 



Manufacturing Company. B. Silliman and J. Hall, pp. 16. 

 New York, 1855. 8vo. 



44. ^Observations upon the Geology of the Mauvaises Terres, Nebraska, 



with Notices of the Geographical and Geological Range of some 

 of the Fossils of that Region. Proc. Am. Ass. Ad. Sci., 8th 

 meeting, Washington, 1854, p. 290. Cambridge, 1855. 8vo. 



45. * Remarks upon a Collection of Cretaceous Fossils from Nebraska, 



and the Absence of Species known in the Southern Extension 

 of the Same Formation. Ibid., p. 290. 



46. * Remarks upon the Results of Extensive and Continued Collec- 



tions of Fossil Species from a portion of the Silurian Rocks of 

 New York, showing the number of species and individuals of 

 each Species Obtained from a limited locality during a Period 

 of Ten Years. Ibid., p. 290. 



47. * On the Reproduction of Similar Types or Representative Species 



in Successive Geological Formations. Illustrated by a Collec- 

 tion of Species of the Brachiopoda from the Niagara and Lower 

 Helderberg Groups of the Palseozoic Rocks of the United States. 

 Ibid., p. 290. 



48. * Red Sandstone of the Connecticut River Valley, and the Proofs 



of its Oolitic or Liassic Age. Ibid., p. 290. 



49. * Remarks upon the Geological Formation of the country along 



the Line of the [Mexican] Boundary Survey, based upon the 

 Examinations of Dr. Parry, made under the Order of Major 

 [W. H.] Emory. Ibid., p. 291. 



50. *The Silurian and Devonian Systems, and the Nature of the Evi- 



dence for Drawing a Line of Separation between the two 

 Systems in the United States. Ibid., p. 291. 



