Senecan 
series <! 
384 The American Geologist. DecembBr, 1903. 
Becraft limestone. In this section the upper part of the New 
Scotland (Shaly) limestone was covered and the tcp was drawn 
at the hase of the Upper Pentamerus ledge, giving a thickness 
of 120 feet for the formation. From this thickness is to he de- 
ducted that of the Scutella limestone, leaving 116 feet for the 
New Scotland beds. 
The Chenango-Otsego region. — The classification of the 
formations in the Chenango valley as given in 1898* the writer 
would now change to the following form : 
Chautauquan series. .. .Chemung stage. 
( Oneonta sandstone. 
Portage stage 1 ,- ••- l . f .• \ Ithaca member.' 
/I nadilla formation j Sherburne member. 
Genessee shale. 
Tully limestone. 
On the map accompanying the above report the Sherburne 
and Ithaca beds were mapped together as one formation ; but 
no name was proposed for it. It is now considered better to 
give this terrane a distinctive name and therefore it is called 
the Unadilla formation.! It is named from the Unadilla river. 
which below New Berlin village, is bordered by steep hills that 
begin in the Sherburne beds, contain the entire thickness of the 
Ithaca beds and are capped by the Oneonta sandstone. It 
ought to be mentioned in this connection that Dr. H. S. Wil- 
liams does not consider the marine fauna succeeding the On- 
eonta sandstone in the Chenango valley "as high as the typical 
Chemung formation of western New York."$ 
The Catskill formation given in the former classification is 
the local facies representing in different localities a time inter- 
val varying in length from that of a portion to the entire time 
of one or more stages. In Broome county in southern New 
York it probably represents in age the upper deposits of the Che- 
mung stage in southwestern New York, while in its typical 
region on the eastern slope of the Catskill mountains in south- 
eastern New York it began as early as the Sherburne beds and 
continued during the remainder, at least, of Devonian time. 
Columbus, Ohio, July 24, 1903. 
* 15th An. Kept. State Geologist (N. Y .) p. 95. 
t See University of the State of New York. Handbook, 19, July, 1903, 
p. 24. 
t U. 8. Geol. Surv., Bull. 210, 1903, p. 96. 
