ANNTVEKSAEY ADDRESS OF THE PRESIDENT. XCl 



stone beds. The Cretaceous formations constitute a large tract of 

 country, extending through the States of New Jersey, Maryland, and 

 Delaware ; they appear in isolated patches in North and South Caro- 

 lina and in Georgia. More extensively developed in the western 

 portion of the latter state, they curve in a wide crescent-shaped tract 

 through Alabama, Mississippi, and Tennessee, to the mouth of the 

 Ohio river. Thence, passing in a narrow band through Arkan- 

 sas, they afterwards expand to an enormous extent, and occupy a 

 great portion of the region between the Mississippi river and the 

 Rocky Mountains, reaching north into the British possessions and 

 south into Mexico. 



Then follows a very detailed account of all the species hitherto 

 found in the United States, the most characteristic of the Crocodilian 

 remains being a nearly entire skull of Thoirtcosaiirus neocesariensis. 

 The species described are 28 in number, belonging to 23 genera, viz. 

 18 Saurians and 5 Chelonians. The work is illustrated by 20 

 beautifully executed lithographic plates, and the author anticipates 

 that, when the western and southern Cretaceous regions shall have 

 been explored, many additions will be made to these remains, nearly 

 all of which have been obtained from the eastern border. 



I stated last year that M. Jules Marcou had discovered and described 

 a remarkable deposit of fossil plants in the Nebraska territory, which, 

 from its position, appeared to be unequivocally Cretaceous, although 

 the forms were considered by Professor Heer to be of decidedly 

 Miocene character. I have now before me an interesting notice on 

 the position of these leaf-beds of the Nebraska by MM. Capellini and 

 Heer, the former of whom visited and examined them in 1863, while 

 the latter gives a detailed account of the species. Notwithstanding 

 his first conviction that the beds containing the vegetable impressions 

 belonged to a Tertiary formation, M. Capellini was convinced by sub- 

 sequent examinations that they occurred at the base of the Cretaceous 

 beds, well marked by the abundance of Inocerarmis prohlematicus. 

 The vast extent of country over which these beds occur in an undis- 

 turbed horizontal position precludes the possibility of any inversion 

 of the strata. 



The following observations of Professor Heer, before describing the 

 species, will be read with interest. The collection consists of 16 

 species (all leaves), four of which are badly preserved. They are all 

 dicotyledonous, and we may in all probability refer 1 to the genus 

 Ficus, 1 to Salix, 1 to Diospyrus, 2 to the genus Populus, and 2 to 

 Magnolia. These are all living genera, and are also found in the 

 Tertiary formation. Comparing these Nebraska plants with the Cre- 

 taceous plants of Europe, we find no identical species ; even the 

 greater part of the genera are difierent. The Cretaceous flora of 

 Hainaut in Belgium, and those of Blankenburg and Quedlinburg, are 

 also quite diff'erent. The Cretaceous flora of Moletein in Moravia 

 offers a greater resemblance ; it contains 2 species of Ficus and 2 

 of Magnolia. There exists, therefore, a certain relationship between 

 the Nebraska flora and that of the Upper Chalk of Europe, although 

 there are no identical species. Hitherto, however, the genera which 



