THE ROMNEY FORMATION OF MARYLAND 369 



In 1889 Professor H. S. Williams apparently correlated in a general 

 way the American Middle Devonian with "the Ilfracombe [England] 

 beds of Phillips, the Givetien limestone of Belgium, [and] the Strin- 

 gocephalien shales or limestones of the Eifel and Hartz regions."^ 

 In 1888 Professor Williams examined in the field typical sections of 

 the Devonian rocks of Devonshire, England, and later stated that 

 "it appears probable that the limestones of South Devonshire repre- 

 sent the general interval between the close of our Corniferous [Onon- 

 daga] and the early part of our Chemung formation."^ Professor 

 Renevier in 1896 classed the Hamilton flags and Marcellus .shales 

 together and regarded them as having been deposited during the 

 same general period of time as the Tentaculite slates (lower part) 

 of Thuringia, Hesse, Nassau, and Bohemia; the Wissenbach or 

 Orthoceras slates of Nassau; the Lenne slates (in part) of southern 

 WestphaHa; and the schists with Phacops potieri of Brittany; all of 

 which were correlated with the Couvinien age or stage, which he gave 

 as the lower one of the Middle Devonian or Eifelien epoch or series.^ 



Dr. Freeh draws the line between the Paleodevonic and the Meso- 

 devonic of New York at the top of the upper Oriskany sandstone, 

 and considers the Mesodevonic as composed of the Ulsterian and 

 Erian seris, in the latter of which are the Marcellus shales, Hamilton 

 beds, and Stringocephalus beds of Canada.^ At an earlier date 

 Dr. Freeh, in his summary of the important occurrences of the Devon- 

 ian, gave the Marcellus shale and Hamilton group as forming the 

 upper part of the Middle Devonian, and correlated them as beginning 

 in the time of the upper part of the Calceola sandalina stage and 

 continuing through that of the Stringocephalus hurtini of Rheinland.^ 

 In this same table the Marcellus and Hamilton considered together 

 are correlated with the upper part of the Eifelien (Calceola shales 



I Compte rendu, Fourth Session, International Geological Congress (London, iJ 

 1891, Appendix A, p. 142; also issued as Report of the Suh -Committee on the Upper 

 Paleozoic (Devonic), by H. S. Williams, C, 1889, p. 22. 



^American Journal of Science, Third Series, Vol. XXXIX (1890), p. 36. 



3 Chronographe geologique, 2d ed. of Tableaux des terrains sedimentaires; Compte 

 rendu. Sixth Session, International Geological Congress (Zurich, August, 1894); Lau- 

 sanne, March, 1897). 



'^Lethaea geognostica, I, Lethaea palaeozoica, Vol. II, Part IV (1902), p. 690. 



5 Ibid., Vol. II, Part I (1897), Table XIX, opposite p. 256. 



