100 ^ 



seven hundred figures prepared, making, when arranged for the en- 

 graver, about fifty quarto plates. The fossil plants from cretaceous 

 formation No. 1 will also be included in the volume, and consist of 

 eighteen species, all of which are supposed to be new to science. The 

 fossil plants of the tertiary era, of which there is a large series, re- 

 markably well preserved and of great beauty, have not yet been 

 studied to any extent. We simply know that they comprise about 

 fifty species, all of which are supposed to be new, and would alone 

 form a good-sized quarto volume. Descriptions and suitable illustra- 

 tions of these plants will be made during the winter or spring. 



The fossil mollusca are arranged in their stratigraphical order, thus 

 bringing at once before the geologist the characteristic fossils of each 

 formation known in the northwest, from the carboniferous to the ter- 

 tiary, inclusive. The work will thus form a standard of reference for 

 those who may wish to study the geology of the west, and will enable 

 the explorer, even though but moderately versed in the science, to 

 determine the age of the formations over which he may be travelling. 

 The fossil vertebrata, which are very numerous in species, a large 

 proportion of which were entirely new to science, have been placed in 

 the hands of Dr. Leidy, the great comparative anatomist of Philadel- 

 phia, who informs us that the drawings are nearly ready for the en- 

 graver. 



The following is a list of the memoirs already published in the 

 transactions of scientific societies on the geology and paleontology of 

 Nebraska and Kansas, by F. B. Meek and F. V. Hayden. 



1. Descriptions of sixty-three new species of Acephala, Gastero- 

 poda and Cejyhalopoda from the cretaceous formation of Nebraska Ter- 

 ritory. — (Proceedings of the Academy of Natural Sciences, Philadel- 

 phia, March, 1856, p. 16.) 



2. Descriptions of new species of Acephala and Gasteropoda from 

 the tertiary formations of Nebraska Territory, with some general re- 

 marks on the geology of the country about the sources of the Missouri 

 river. — (Proc. Acad. Nat. Sci. Pa., June, 1856, p. 16.) 



3. Descriptions of new fossil species of mollusca, collected by Dr. 

 F. v. Hayden in Nebraska Territory, together with a complete cata- 

 logue of all the remains of invertebrata hitherto described and iden- 

 tified from the cretaceous and tertiary formations of that region. — 

 (Proc. Acad. Nat. Sci. Pa., November, 1856, p. 22 ) 



4. Descriptions of new species and genera of fossils collected by 

 Dr. F. v. Hayden in Nebraska Territory, under the direction of Lieut. 

 G-. K. Warren, U. S. Topographical Engineers, with some remarks on 

 the tertiary and cretaceous formations of the northwest, and the 

 parallelism of the latter with those of other portions of the United 

 States and Territories. Communicated by permission of the Secretary 

 of War —(Proc. Acad. Nat. Sci. Pa., May, 1857, p. 34.) 



5. Descriptions of new organic remains from northeastern Kansas, 

 indicating the existence of permian rocks in that Territory. — (Trans- 

 action of the Albany Institute, vol. IV — read March 2, 1858.) 



6. Descriptions of new organic remains collected in Nebraska Ter- 

 ritory in the year 1857, by Dr. F. V. Hayden, geologist to the ex- 



