48 NEW YORK STATE MUSEUM 



tensive one being exposed in the Fellows falls ravine 3 miles west of 

 Tully. Here also occurs with some frequency the large trilobite 

 Homalonotus dekayi which is very rare in more westerly 

 outcrops but even more abundant in Madison county. The composi- 

 tion of the fauna as a whole is interesting in the extreme and no 

 more favorable collecting ground could be indicated to the student 

 of fossils than the several outcrops of this formation. 



Moscow shale 



In western New York there lies between the Ludlowville and 

 Moscow shales a limestone which has usually been termed the En- 

 crinal limestone though it is now recognized that this name was 

 applied by the early geologists and has been since, to limestones 

 lying at different horizons. This dividing limestone is now known 

 as the Tichenor and if there is any representative of it so far to the 

 east as this, it may be the summit layer we have just considered 

 under the foregoing caption. The Moscow shales are a soft 

 dark gray argillaceous mass that weather to a much lighter shade 

 and attain a thickness of 180 feet. There is but little lime carbonate 

 in the rocks, represented by occasional irregular concretions and thin 

 calcareous lenses. The formation as a whole is somewhat darker 

 and less calcareous and also less fossiliferous than in its extent 

 westward. The upper limit of the formation is the base of the 

 Tully limestone. 



These rocks are seen in the Bucktail ravine at Spafford valley and 

 in the ravines and field outcrops on the east side of the Otisco valley ; 

 along the highway at the foot of the escarpment on the Tully road, 

 1 y 2 miles southeast of Vesper ; along the dugway road leading north 

 from Tully Center ; in a ravine 1 mile northeast of Tully ; along the 

 highway and hillside 1^2 miles north from Tully station; along the 

 creek and on the hillside 3 miles north of Apulia station and at 

 Tinkers falls in the town of Truxton. 



Fossils are on the whole not very abundant in the shales but the 

 concretions and calcareous lenses contain many brachiopods and 

 small lamellibranchs. While the fauna is a varied and compre- 

 hensive one it is less profuse and less well preserved than that of 

 the Ludlowville shales, from which it differs only in minor respects. 



