294 NEW YORK STATE MUSEUM 



difficult to distinguish the line of division be- 

 tween this formation and the Hamilton. At the 

 point where the division has been made the 

 shales suddenly become more arenaceous in 

 character though they still retain their black 

 color, except that when exposed they weather 

 brown. The fossils are : 



1 Chonetes inucronatiis H. a 



2 Glyptocardaa speciosa H. a 



3 Coleolus tenuicinctum H. v 



4 Goniatites discoideus H. c 



Feet Total 



Onondaga limestone 85—471 



A massive gray limestone in which large quan- 

 tities of chert may be found in thin layers. 

 According to the statement of Mr H. Ingraham, 

 who drilled a well through this formation about 

 a quarter of a mile south of Clarksville, the 

 upper nine feet are entirely clear of chert, below 

 this are 15 feet in which the chert is very abun- 

 dant. In the lower part of the formation chert 

 was encountered but in rather small quantities. 



There is an outlier of this formation which 

 forms the top of the ridge east of the village, 

 and when the Oniskethau creek cut through this 

 ridge the outlying area was cut off from the rest 

 of the formation. This outlier was mentioned 

 by Mr Darton who noted the infrequency of 

 such outliers in this formation. 1 The measure- 

 ment of this formation was taken at the foot of 

 Bennett rather than Wolf hill, because the ex- 

 posure there permitted it to be more accurately 

 done. The fossils are : 



1 Meristella unisulcata (Con.) II. r 



2 Leptaena rhomboidalls (Witch.) II. & C. r 



3 Atrypa reticularis (Lin.) Dal. an 



4 A. spinosa //. a a 



5 Pentamerella arata (Con.) II. c 

 <; Stropheodonta coneava //. r 



7 S. tcxtilis //. rr 



8 Spirifer duodenarius //. ;i 



9 S. maorus //. (?) rr 



10 Dalmanites (Coronura) aspectans (Con.) II. rr 



11 Phacops criartata /•'//-. pipa //. rr 



12 Platyceras duniosun] Con. c 



13 Cyrtooeras sp. rr 



14 Zaphrentis gigantea (LeSueur) Edw. & If. rr 



15 Z. cornioulum (LeSueiir) Edic. &• H. rr 



16 Fenosiclla biseriata H. rr 



J N. Y. State Geol. 13th An. Rep't, p. 242. 



