352 NEW YORK STATE MUSEUM 



back's house the upper part of the Decker Ferry formation is 

 shown and the following species were obtained. 



1 Favosites sp. 



2 Atrypa reticularis Linne 



3 Camarotoechia litchfieldensis Schu- 



chert 



4 Chonetes jerseyensis Weller 



5 Leptaena rhomboidalis Wilck. 



6 Rhynchonella ? lamellata Hall 



7 Spirifer sp. 



8 Stropheodonta bipartita Hall 



9 Pterinea cf. emacerata Con. 



10 Dalmanites sp. 



11 Proetus pachydermatus Barrett 



12 Beyrichia sp. 



The Cobleskill limestone is obscurely exposed in the field be- 

 yond, where also were found the thin limestone bands crowded 

 with Whitfieldella sulcata Van. and Spirifer 

 V a n u X e m i Hall, and which mark the upper limit of the 

 Cobleskill. 



Passing from this station northeastward into Sullivan county 

 no outcrops of the Cobleskill have been observed. Throughout 

 Sullivan county there is but little opportunity for the examina- 

 tion of the Siluric and Helderbergian rocks. The cliffs so promi- 

 nent north - from Port Jervis between the Neversink river and 

 Shawangunk mountain become low in Sullivan county and almost 

 entirely disappear. Outcrops in the valley are but rarely seen. 

 There is an old limekiln on the land of John Olcott a short distance 

 north from Wurtsboro located near the outcrop of the Esopus 

 shales. There is however nO' outcrop of limestone in the vicinity, 

 the rock used for burning lime being gathered from the fields. 



Just over the county line north from Spring Glen station^ in 

 Ulster county, there is an old quarry near the east bank of the 

 now abandoned Delaware and Hudson canal. The rock as here 

 exposed is a thin bedded limestone with some layers of shale and 

 appears to belong to the lower portion of the Manlius. 



Two miles southwest from Ellenville there is a small but con- 

 spicuous outcrop of Helderbergian limestones which rise above 

 the general level of the valley. The outcrop is near Sanborn 

 creek on the land of L. Y. Hall. Lime is burnt at this place but 

 only in small quantities. A similar outcrop is seen at John Horn- 

 beek's quarry a short distance south of the Eastern Reformatory 



^This outcrop and the two following are noted by Mather. Geol. N. Y. 

 1st Dist. 1843. p. 322-33- 



