THE ROMNEY FORMATION OF MARYLAND 365 



Maryland and Pennsylvania to New York, have been much more 

 frequently correlated with the Hamilton beds of New York. Pro- 

 fessor James Hall and other paleontologists have identified collections 

 of fossils from these rocks in northern West Virginia, and from inter- 

 mediate localities between that state and New York, as composed 

 of Hamilton species. If the various geological maps, reports, and 

 papers describing the Devonian formations from West Virginia to 

 New York are put together and considered, it will be found that this 

 correlation is strongly supported by visible continuity. Furthermore, 

 the stratigraphic position of these beds strongly supports this correla- 

 tion. 



The paleontological data are as yet much more extensive regarding 

 the Hamilton beds than for the Marcellus shale. The total number 

 of species recorded by the writer from the Hamilton beds of Mary- 

 land is 147, of which 21 are limited to Maryland, leaving 126 identical 

 or closely related species which also occur in New York. An enumer- 

 ation of the totals for the New York Devonian formations shows that 



3 identical species occur in the Helderbergian series; i identical, in 

 the Oriskany; 6 identical, in the Schoharie; 17 identical, doubtfully 



4 more, and 2 affiliated, in the Onondaga ; 47 identical, i more doubt- 

 fully, and 7 affiliated, in the Marcellus; 92 identical and 32 affiliated, 

 in the Hamilton; 2 identical, in the TuUy; 4 identical and i affiliated, 

 in the Genesee ; 2 identical, in the Portage ; 4 identical and 2 affiliated, 

 in the Naples; 10 identical and i affiliated, in the Sherburne; 55 

 identical, 2 more doubtfully, and 9 affihated, in the Ithaca; and 18 

 identical, 4 more doubtfully, and 3 affiliated, in the Chemung. Adding 

 these numbers, the total number of entries for each New York forma- 

 tion is as follows: Helderbergian series, 3; Oriskany sandstone, i; 

 Schoharie grit, 6; Onondaga limestone, 23; Marcellus shale, 55; 

 Hamilton beds, 124; Tully hmestone, 2; Genesee shale, 5; Portage 

 beds, 2; Naples beds, 6; Sherburne sandstone, 11; Ithaca beds, 66; 

 and the Chemung beds, 25. Judging from the number of entries, 

 it is then seen that the Maryland beds show the closest relationship 

 with the Onondaga, Marcellus, Hamilton, Ithaca, and Chemung 

 formations of New York; and especially with the Marcellus, Hamil- 

 ton, and Ithaca. On examining the total number of entries for these 

 three formations, it is found that the Marcellus has 44.3 per cent, as 



