TYPICAL SHERBURNE 427 



series of Ulster County, which has a total thickness of about 3,000 feet 

 and is succeeded by the red beds of the Catskill formation. Xear N'obles- 

 ville, Otsego County, in the Butternut Valley, Prosser found ''smooth 

 greenish sandstones, in the midst of which are blocky shales in which 

 Rkynchonella [Hypothyris] veniistula Hall is common/" With these 

 occur 



Spirit er mucronatus (Con.) it 



Atrypa reticularis (Linn.) r 



Tropidoleptus carinatus (Con.) rr 



This is evidently the closing phase of Hamilton deposition, marked by 

 the invasion of this region by Hypothyris cuboides just before the inaugu- 

 ration of the Sherburne type of sedimentation. 



//. veniistula is again found in this same horizon in Lawrence town- 

 ship, about three quarters of a mile south of Mount Vision, on the eastern 

 side >oi Otego creek. Here it is associated with Paracyclas lirata and 

 apparently also with Spirifer mucronatus and Palceoneilo suhemarginata 

 (?). Between the Unadilla and the Susquehanna rivers the Sherburne 

 is still for the most part unfossiliferous, though the intercalated shales 

 frequently carry a restricted Hamilton fauna. This is, however, more 

 often restricted to certain levels within the formation, the great bulk of 

 which is barren. 



In Maryland township, south of the village of Schenevus, the Sher- 

 burne has yielded the following fossils about 175 feet above the Hamil- 

 ton :i« 



1. Spirifer tiillius Hall (r) 



2. Tropidolpptus carinatus (Con.) 



3. Leda diver sa Hall (r) 



4. Cypricardella temiistriata Hall (rr) 



5. Falwoneilo constricta (Con.) (it) 



6. Jilodiomorpha cf. siihalata var. chemungensis Hall (rr) 



Xear Chase ville, rocks of this series, comprising shales and sandstones, 

 have yielded, in the lower part, near the Hamilton boundary: 



1. Tropidoleptus carinatus (Conr.) e 



2. Spirifer mucronatus (Conr.) r 



3. Spirifer tullius Hall c 



Forty-five feet higher a coarse-grained sandstone, sparingly fossiliferous, 

 has furnished : 



1. Lioi'hynchus mesacostalis Hall (r) ' . 



2. Crania cf. leoni Hall (c) 



3. (1) Cryptonella eudora UaW (rr) 



1" Prosser : Loc. cit. 16th Ann. Rept., p. iOl 



