TABULAR VIEW. 
23 
In Connecticut, Dr. Percival with Prof. C. U. Shepard have investigated the geology and 
mineralogy of the State, which includes the Primary, New Red Sandstone and Trap. 
In New-Jersey and Pennsylvania, Prof. H. D. Rogers, and in Virginia, Prof. W. B. Ro¬ 
gers, have been occupied in exploring the formations from the Primary, through all the older 
fossiliferous rocks, the Carboniferous period, New Red, Oolite, Greensand and Tertiary. 
In Maryland, a geological and topographical survey of the State has been in progress for 
several years, by Prof. Ducatel and J. H. Alexander, Esq., and the work is now nearly com¬ 
pleted : a local survey of the coal region of Alleghany county has been made during the past 
summer, by Prof. Aikin. 
Prof. W. C. Booth has made a geological survey of Delaware, giving a complete account 
of all its formations and mineral productions. 
In the Ohio survey, under the direction of Mr. Mather, the reports of Dr. Locke, Messrs. 
Whittlesey, Briggs and Foster, have elucidated in a great measure the geology of the State. 
Dr. Hildreth had previously done much towards illustrating this subject, and his valuable 
papers in the American Journal of Science are fully appreciated by those who have any know¬ 
ledge of these formations in the west. 
In Michigan, Dr. Houghton has been actively and zealously engaged in prosecuting to its 
completion, a very thorough survey. 
In Indiana, Dr. Owen, under the direction of the authorities, and partly upon private en¬ 
terprise, has developed the great geological features of that State ; and, with Dr. Locke, has 
more recently been engaged in the lead region of Illinois, Wisconsin and Iowa. 
In Tennessee, Dr. Troost has been for several years engaged in a geological survey of the 
State, which has developed an interesting series from the Primary upwards. 
Mr. Nicollet has recently been investigating the formations west of the Mississippi, and his 
discoveries in that region have proved highly satisfactory and important. 
In Georgia, Dr. Cotting has completed a survey of the State, and published a report upon 
its mineral productions. 
North and South Carolina had been previously investigated by Professor Olmsted and Mr. 
Vanuxem. 
It will thus be seen that much the greater part of the territory east of the Mississippi river 
has been partially or entirely explored under the direction of the respective State governments. 
The remainder will doubtless soon be investigated, either under the same auspices, or by 
private enterprise. Much yet remains to be done in the way of harmonizing views, and 
bringing the nomenclature to some general standard. For as these surveys have mostly been 
pursued quite independently of each other, it has led to the adoption of terms, which, however 
applicable, cannot all be well retained without overburdening the science with synonyms. 
The comparative development of the rocks and groups in different parts of the Union, will 
probably be the test of nomenclature ; since local or geographical names have been generally 
adopted, and at the present time meet with most favor. 
The results of all these investigations have proved the existence of the rocks of the New- 
