WAVERLY GROUP. 75 



the general dip of the strata, he beheves that he descends to lower 

 beds, when, moving eastward, he really ascends to the cliffs of 

 Flat Rock ; proceeding on to Point of Barques, he still is under the 

 impression that he descends to lower horizons. From Point of 

 Barques toward the Lighthouse, the section is actually changed 

 into a descending one, which is considered by him as a direct down- 

 ward continuation of the former. Unfortunately, this section is 

 laid across a synclinal undulation of the formation, and begins at 

 one end with the same rock beds (Marshall sandstone) which on 

 the other end are found very near the base (grindstone ledges). 

 Under the impression that he has all the while descended, he 

 stands again on the horizon from which he started. An almost un- 

 interrupted section through all the above-described rock beds can 

 be seen in Willow Creek, 5 miles above its mouth ; the layers be- 

 tween the coarse-grained upper sandstone and the grindstone series 

 are particularly well denuded there in the bed and banks of the 

 creek. 



The sand-rock ledge of Point of Barques Lighthouse, whose fos- 

 sils I have enumerated, is designated by Prof. Winchell as the 

 dividing stratum between his Huron shales and his Marshall group ; 

 the sand-rock bed is pretended to represent the Devonian fauna, • 

 the shales above it, the fauna of carboniferous character. He enu- 

 merates 19 species of fossils found in the sand rock to prove its 

 Devonian character. Six of them are identified with Hamilton 

 species, identifications which must be questioned, and 13 species 

 are newly described by the Professor, which, as new forms, can have 

 no great value in the instituting of comparisons, their generic types 

 being as much at home in the Devonian as in the carboniferous 

 rocks. The shales above this sand rock contain a majority of all 

 the species in common with it. The conformity of rock material 

 and stratification in this part of the formation, above and below 

 the imaginary division line between the Devonian and carbonifer- 

 ous deposits, is so perfect that no one could accept this stratum as 

 the terminal deposit of the Devonian ocean, even if the fact were 

 ignored that at least 500 feet of rock beds below this horizon 

 present the faunal characters of the Cuyahoga shales of Ohio, 

 which form the upper division of the Waverly group. 



From Lighthouse Point southward, as far as Forestville, in 

 the north part of Sanilac County, rock beds approximately of the 



