Prosser — Hamilton and Chemung Series. 



1 85 



The discovery of R. venustula at Nobles ville extends its distribution 

 thirty miles farther to the southeast than heretofore reported ; and on account 

 of the very limited known range of the species this discovery is regarded as 

 very strong evidence in support of the horizon considered in this report as the 

 top of the Hamilton formation. The species was also noted at this position 

 in the geological series at a few other places in Otsego county, and so it seems 

 to the writer that this question as to where the line of division Ketween the 

 Hamilton and overlying formation is to be drawn in that county, should he 

 finally settled by this evidence. This seems a perfectly tenable position, 

 especially since the closely related species, R. venustula, of New York, and 

 M. cuboides, of Europe, are regarded as occurring at very nearly the same 

 geologic horizon. In the words of Professor H. S.Williams: "The correlation 

 thus established is one not merely of homotaxy, but within relatively short 

 limits, of contemporaneity; and that the Tully limestone may be said to have 

 been deposited during the period of deposition of the Cuboides Schiehten, of 

 England, Belgium, France, Germany, Russia and the East. 11 1 



Along the road and a small stream to the southeast of Noblesville, are 

 occasional exposures of smooth, unfossiliferous shales and thin sandstones 

 belonging in the Sherburne formation. 



■XXI B % . At the summit of the hill, 360 feet by the barometer .above 

 the ledge with Rhynchonella venustnda, are quite fossiliferous, arenaceous 

 .shales and thin sandstones affording the following species: 



1. Spirifer mesastrialis, Hall. (c) 



2. Spirifer mucronatms (Con.), Bill. (rr) 



3. Jili ynchoriellci (fJamarotcechiai) exvmia, Hall (?). 



Rather small specimens with sharp plications. 



The specimens of Spirifer mesastrialis are typical and common, indicating 

 these rocks to be in the Ithaca formation. It is probable that the base of the 

 Ithaca beds is a hundred feet lower than the summit of the hill, and that the 

 high land between Noblesville and Gilbert's lake belongs in this formation. 



XXI C n . At the three corners on the road following the tow nship line 

 between New Lisbon and Laurens, one-third of a mile west of Gilbert's lake, 

 are rather coarse shales that are very fossiliferous, especially thin layers w hich 

 are largely composed of Spirifer mesasi/rialis, Hall. A very brief time w as 

 spent in collecting, and only two other species were noted, viz.: Atrypa 

 reticularis, (Linne), Dal., and Tropridoleptits earinatus (Con.), Hall. This 

 locality is, according to one barometric reading, seventy feet lower than 



1 Bulletin Geological Society of America, Vol. I., p. 49i>. 



