index. F\ 423 



Page. 



Zigzags of V, VI, and VII, 13 



" at Dick's Hill bridge, Wheatfield t., 390 



Formation No. Ill, Trenton limestone. 

 " Horse valley, Toboyne t., nowhere visible, 352 



Formation No. UT a, Utica slate. 



** in Hor3e valley, Toboyne t., ... 43,352 



" sulphur springs at contact of III a, b, 



Formation No. Ill b, Hudson River {Loraine) slate. 



11 in Horse valley, Toboyne t., 353 



Formation No. IV a, Oneida conglomerate. 

 i: exposed in only one place, in the ravine of Run gap, Saville t., . . . 322 

 " not gapped in Tyrone t., . . 370 



Formation No. IV b, Lower, red, Medina sandstone. 



11 well displayed in the counties north-west of Perry, but not distin- 

 guishable from IV c in this region, 



Formation IV c, upper, white Medina sandstone. 



" described in general, IV a b c, 43 



" thin, runs outside Carroll t. line in Cumberland co., 159 



" in Greenwood t. makes Slaughterbeck hill, 216 



" in Madison t. has five outcrops, . . 253 



" in Rye t. only about 100' thick, and makes the south crest of Blue 



mountain, mostly within the limits of Cumberland county, . . . .310 

 u at the Susquehanna River gap seen to be overthrown so as to dip 



southward, 310 



11 in Spring t. makes a crest in Cumberland co., 333 



" in Toboyne t. makes eight mountains, 354 



Formation No. V a, Clinton shales and fossil ore. 



" described and compared with New York, 44,45,46 



'• two beds on Burn's farm, Blue mtn, 159 



" concealed along rocky, woody slope of Conococheague mountain, in 



Jackson t., 231 



" well exposed on the Chestnut ridge arch, 231 



" best exposed in the two gaps of Sherman's creek through Chestnut 



ridge, 232 



" detailed in Bistline Mill section, Madison t., 255 



" hard to trace in Toboyne t., . . 357 



" becomes calcareous in its upper part, 358 



" two outcrop belts in Tyrone t., 370 



Group V a I, Clinton lower shales. 



" described generally, 47 



" exposed near Sterrett's gap, 159 



" well exposed in Madison t. on mountain road from Buffalo mill to 



Sandy hill, on the Conococheague anticlinal, 254 



" 500' thick, makes a broad cultivated crest to Blue mountain, in Rye 



t., and Spring t. no good exposures, 311,335 



" concealed by rocks on mountain in Saville t., 323 



Group of V a 2, Clinton iron S&. and black ore. 



" described generally, variable, . . . 48,50,93,94 



• makes a ring wall around Slaughterbeck hill, Greenwood t, . . . . 216 

 " makes Chestnut hills in Jackson t., 230 



