INDEX 



Page 



Amphllichas, mentioned.- 65 



Ampyx, mentioned 52,53 



Amfjyxina powelli, mentioned 27 



Apatowiphalus, mentioned 7 



Arbuckle limestone, divisions of 70 



Arctinuras, mentioned 65 



Ardwell group 85 



Arcnig formation, Upper Canadian age of 83 



Ashglllian of lOugland probably Medinan in 



ago 86 



Athens shale, fossils of 27 



northern extent of 51 



Balclatchic fauna, relations to Craighead 



limestone fauna 84 



formation, fossil evidence on age 



of 53,85 



lower age limit of 50 



Barren flagstones of the Qirvan section 85 



Bassler, R. S., mentioned 1,61,71 



Becsie formation, age of 82 



Blount faunas 57 



British and American definition of Silurian 



at variance 63 



Buffalo River series absent in Appalachian 



Valley 79 



unconformably over- 

 lain in Mississippi 



Valley 77 



Butts, Charles, mentioned 58 



work of in Appalachian re- 

 gion 71 



Calymene, mentioned 51 



Campbell, II. D., mentioned 2 



Canadian deposits in northern Newfound- 

 land - 81 



Cause of difflculties in correlating European 



and American formations 64 



Chambersburg limestone, stratigraphic posi- 

 tion and fauna of 59 



Chariocephalus, mentioned 7 



Cincinnatian series 79 



' Close discrimination of species, need of 9 



Coelospira, first appearance of 87 



Coniston limestone series, natural base of 



Silurian system 86 



Coral fauna of the Coniston limestone series. 86 



Correlation by diastrophic criteria 68 



inadequacy of former methods of. 67 



of Minnesota formations, note-- 67 



table 73 



basis of generalized time scale 73 



formations in Baltic region. 88 



formations in Britain. 82 



formations in Mississippi 



Valley 77 



Page 

 Correlation table formations in Norway and 



Sweden 87 



formations in Ohio Valley. 78 



generalized comments on _ _ 75 

 G.rvan district, Scotland, 



supplementary notes on . . 83 

 northern Appalachian for- 

 mations 81 



notes on Oklahoma for- 

 mations - -_ 67 



southern and middle Appa- 

 lachian formations 79 



Craighead quarry limestone 84 



Cybeloides, mentioned 9 



Cybelopsis, mentioned-. 9 



Cyclopyge (Aeglina), mentioned 6 



Cyclopygidae, mentioned.- 7 



Decorah Bryozoa in Baltic region 60 



faunas, northern origin of 60 



Deposits of Blount age absent in Maryland 



and Pennsylvania 67 



Dicellograptus cf. complanatus in Sylvan 



shale-- - 66 



Didymograptus biflrlus, mentioned 83 



Dionide, mentioned 49 



Drummuck formation of Scotland, age of 61,68 



Durness limestone, relations of to American 



Middle and Upper Canadian formations-. 83 



Ellis Bay formation, position of in time scale. 82 



Encrinurus afl. punctatus, mentioned 61 



Etage 3c (Orthoceras limestone), age of 88 



Faunal evidence bearing on base of Silurian 



in Britain-.- --- 87 



Faunas of the Blount group 57 



Fcnestella, first appearance of 87 



Galena limestone, age of 78 



Glaphurina brevicula, new species 46 



falcifera, new species 40 



lamottensis, new species 46 



mentioned 8,9 



Olaphurus decipiens, mentioned 8,44 



latior 44 



mentioned 7 



pustulatus, described 42 



Graptolites, limitation of value in correlation. 48, 87 



Gun River fornmtion, age of 82 



Ilemitrypa, first appearance of 87 



Interprovincial correlations, present status of. 72 

 Introduction of new (auoal elements, import- 

 ance of in correlation.- 68 



Irvingclla, mentioned 7 



Isotelus, medium eye of, mentioned.— 27 



Jones, O. T., mentioned 83,84 



Juniata and Queenston sandstones 81 



Keisley limestone of England, age of 61, 04, 60 



Kimmswick limestone 78 



99 



