HAMILTON GROUP. . 57 



another outcrop of rocks faces the bay, which are the next higher 

 beds succeeding those last mentioned. The lowest portion of 

 them is a drab-colored, porous dolomite, full of Stromatopora 

 monticulifera and Stromatopora Wortheni, Cyathophyllum pro- 

 fundum, Favosites Hamiltonensis, etc. The upper portion is 

 laminated with seams of a black, calcareous, combustible shale, 

 which contain an abundance of Strophodonta erratica, ramulets 

 of Favosites digitatus, and other fossils. The thickness of this 

 dolomitic series is about 8 or 10 feet. Above it is a stratum of 

 soft blue shale of variable thickness, from i to 4 or 5 feet, which 

 contains many finely preserved fossils, such as : Cyathophyl- 

 lum profundum (Acervularia profunda), Cyathophyllum Hough- 

 toni, Cyathophyllum Hallii, Cystiphyllum Americanum, Favo- 

 sites Hamiltonensis, Favosites nitella, Aulopora conferta, Syringo- 

 pora, Stromatopora plana, Stromatopora monticulifera, Stromato- 

 pora Wortheni, a great variety of Bryozoa, Atrypa reticularis, Spiri- 

 gera concentrica, Spirifer mucronatus, Spirifergranuliferous, Cyrtina 

 Hamiltonensis, Strophodonta erratic, Terebratula Linklaeni, Cra- 

 nia Hamiltoniae, Crania crenistria, Crania(?) radicans Winchell, Pho- 

 lidops, Phacops bufo, etc. Above these shales follow drab-colored, 

 porous dolomites similar to the beds at the base of the section, 

 and containing about the same fossils ; from 10 to 15 feet of them 

 terminate the outcrops in that locality. 



Several outcrops comprising about the same series of strata are 

 found by following the shore westward for two or three miles. About 

 three miles east of Khagashewung Point, the section through the 

 heretofore considered beds is continued into higher strata (the so- 

 called buff magnesian limestone of Winchell), which I believe to be 

 equivalent with the Stromatopora beds composing the bluffs of 

 Petosky. The section is as follows : Lowest, partly submerged 

 under the water, are blue, hard limestones full [oi Stromatopora, 

 Cyathophyllum profundum, and Favosites Hamiltonensis ; above 

 them are alternating seams of nodular limestones and of black, 

 combustible shale, crowded with fossils similar to those in the for- 

 mer stratum. Next follow several feet of gray limestones ; some 

 beds of them are of very fine grain, like lithographic stone, but 

 brittle ; they contain but few fossils ; a fossiliferous seam, with 

 Cyathophyllum profundum, Favosites, and other fossils, overlies 

 them ; then come again from 6 to 8 feet of the brittle, smooth- 



