370 CHARLES S. PROSSER 



of Couvin) together with the entire Givetien (which is composed 

 in ascending order of the red sandstone and conglomerate of Vicht 

 and Stringocephalus limestone of Givet) of Belgium; while they are 

 given as equivalent in England to the Ilfracombe beds, with probably- 

 additional ones below and above, of North Devon; and to the upper 

 part of the Calceola shales of Hopes Nose and Ogwell House, suc- 

 ceeded by the diabase and scale stone of the Ashfrington series and 

 the Stringocephalus limestone of South Devon. 



In another part of the work Dr. Freeh, in comparing the North 

 American and Rhenish Devonian, said: 



In the Corniferous [Onondaga] limestones the faunal diversity is less sharply 

 defined than in the lower formations; but in this case, as in the higher Hamilton 

 group, still distinctly perceptible. The latter is often developed in the form of 

 sandy marl and calcareous sand, and the peculiar faunal similarity with the 

 Rhenish Lower Devonian partly rests upon this harmony in facies. But, on the 

 other hand, the marl (Moscow shale), for example, where it forms on Cayuga 

 Lake the greater part of the Hamilton, has a perfect agreement in facies with the 

 Calceola marl, and likewise the Encrinal limestone reminds one of a similar inter- 

 stratified limestone The fauna of the American Middle Devonian, whose 



chief representatives the Hamilton group contains, is, notwithstanding some 

 corresponding features, yet, on the whole, so different that one must assume the 

 existence of a special sea province also in Middle Devonian time differing from 

 the Rhenish.^ 



Finally, at the close of this section is the statement that the Mar- 

 cellus shale corresponds to the lower part of the stage of the Maene- 

 ceras ierebralum^ of Rheinland, which Dr. Freeh puts in the stage 

 of the Stringocephalus burtini. 



De Lapparent considers the Middle Devonian of North America 

 as composed of the Corniferous (Onondaga) limestone, Marcellus 

 shale, and Hamilton beds.^ The Marcellus shale he correlates with the 

 upper part of the Eifelien stage and the lower part of the Givetien, 

 while the Hamilton beds represent the remaining and greater part 

 of the latter stage. He also gave the lower Marcellus shale as rep- 

 resenting the upper part of the shales of Ogwell House, and then the 

 remaining portion together with the Hamilton beds as synchronous 

 with the Ilfracombe or Plymouth beds of Devonshire, England.'^ 



Professor Kayser in the table of the Devonian formations of New 



I Ibid., pp. 214, 215. ^Ibid., p. 216. 



sTniite geologique, 4th ed. (igoo), p. 857. 4 Ibid., p. 869. 



