BUFFALO SOCIETY OF NATURAE SCIENCES 29 



sufficiently obdurate to make it very difficult to separate the 

 fossils from the matrix. 



The Tichenor limestone is exposed at Eighteen Mile creek 

 below the railway bridges and in the lake cliffs south of the 

 mouth of the creek. It dips under the lake just north of the 

 mouth of Pike creek. It forms cascades in the south branch of 

 Smoke's creek at Windom and in the north branch at the Town 

 Line Road. It is the base of the dam at Springbrook and forms 

 a series of cascades in Buffalo creek at Bullis Road. The Bullis 

 Road outcrop of this limestone is perhaps the best in Erie county. 

 Here the layers are separated by thin, shaly layers and the upper 

 layers are more nearly hard calcareous shale than limestone, yet 

 the entire formation, including the shaly separations, is hard 

 enough to have allowed a block nearly four feet thick to drop out 

 of the cliff at one point. The middle layers are composed entirely 

 of fossils mostly large cyathophylloids, favositids and crinoidal 

 stems with an abundance of the characteristic lamellibranch 

 Mytilis, the Spirifer granulosus, and bryozoa. The favositids 

 form large heads often more than a foot in diameter and many of 

 the crinoidal stems are a foot or more long and three-eighths of an 

 inch thick. 



Moscow Shale. 



The uppermost member of the Hamilton beds is the gray 

 shale which has taken its name from a fine exposure at the village 

 of Moscow, in Livingston county. This shale lies immediately 

 above the Tichenor limestone and is limited above in Erie county 

 by a pyritiferous layer of shale. It includes in its upper layer a 

 band of concretionary limestone two inches thick at Springbrook 

 but varying with the locality. The shale is uniformly gray, 

 rather free from cleavage planes and it weathers to a sticky, gray 

 clay. The bottom layers, especially those immediately above the 

 Tichenor limestone, are highly calcareous and firm enough to 

 break out in rough blocks. It contains occasional thin layers of 

 concretions or concretionary limestone. The lowest layers 

 immediately above the Tichenor limestone are very fossiliferous. 



Its contact with the underlying Tichenor limestone is well 

 defined. Its upper limit is well marked by a pyritiferous band, 

 which shows in a cliff face as a brown band. 



