SILLERY FORMATION 661 



Page Plate 



Sillery formation 443 



Silurian 28 



Changes during, compared with Ordovician GOG 



coral faunas, Distribution of 509 



deposits 469, 471 



(early) -Ordovician (late) period of activity 468 



faunas 487 



formations, Absence in Appalachian Valley troughs of 545 



in Kentucky and Tennessee 526 



Nashville dome 579 



oscillations 422 



province in Indiana and Tennessee 291 



routes of migration 485 



seas, Varying stages of 339 



system, Thickness of 383 



time, Expansion of 380 



Silurian and Devonian overrlaps 307 



Siluro-Ordovician boundary 585 



Siluro-Devonian transition 579 



Silver Creek dolomite , 28 



Similarity in lithologic character and stratigraphic position not 



proof of contemporaneity 522 



Simpson formation 648, 662, 663 27 



Sink-holes in Ozarkian region 537 



Sinuites fauna 322 



Sinuopea, new genus 630 



sweeti ( ? Whitfield) 639 



Skunnemunk Mountain trough, Atlantic connection of 573 



Smith, J. P., on migration of faunas 491 



Snake Hill shale 27 



Sneedville limestone 545, 563 28 



Snowbird formation 618 



Sodus shale 28 



Solenospira prisca ? 654 



Solution caverns, Deposits in 466 



channels near Clarksville, Missouri 455 



Southern Appalachian Valley, Map of Ordovician outcrops in 



Southgate shale of Eden group 21)7 



Spergen fauna 492, 5X)8 



Ancestry of 498 



in Montana 302 



in southwestern Missouri 302 



limestone 583 29 



Recurrences of 301, 515, 593 



Spirifer lateralis 5!) 4 



neglectus 594 



rostellatus 594 



subcardiifonnis 5!) 1 



Splitting of sandstone and shale formations 527 



