== + 
north | mississippi vatuer Mississipp! VALLEY EUROPEAN AVONIAN CoNoDONT zoKES sampte | CORAL 
AMERICAN FORMATIONS. CONODONT ZONES. ZONES NUMBERS AC HIDEO) 
Senies 
= Yo 
GLEN DEAN Jineatus-Klagognathodus meni 
= 
2 
= | manoivapunc Gnathedus bilineatus-Cavuygnathus cristalua pan climes 
7 GOLCONDA 91 Gnathodus girtyi collins ee bce 
5 CYPRESS cullY 
0 | mloennawen 
= 
é aoorva9 
Goathedus bilineetus-Cavusgrathus cheractus — 
Gnethodvs mononodosus 
culls 
cro7 
st. GENEVIEVE Gres 
Mestogneihus| beckmenni-anethedus bilinectus 22 
= crot 
culi« 
D9 
o 
Apstognetnus geminn- Cavusgnothus 
Apstognathus gemins-Covusgnathus on [b2a2=3 
sr Louis arr 
Tepnregnetnus| varians- Cavusgnatnus- Apetognetnus Bn 
s45 
2 [ener reorERrONp wares NEALE aaa 
g Covusgnotnus unicornis - Apetognatnus 
WAReAW = 29 
iu cul 
Pa cis 
ia <5, 
| neon Icnethedial texernteeeTepnresnethts Ne Conodonts 
3) 26 
< c2s5 
BS 
Hestegnainosilbeckmenni=lFalvancinvs)ielsehott 
UrreR BURLINGTON Bactrognathus - Taphrognathus eat 
c 
cia 
Gretheeus/entetexenus)- Pelvenstnus ltecinates 
IDOLE ase LOWER 
1 
Bactrognathus - Polygnathus communis A A ere oe 
FERN GLEN z 
Pueudopolygnsinus |e -r-longiposticus 
233 
732 
“seoauia Groteean Inet 
A Polyaneihis tecinatus 
2. Pseudopolygnathus multistriatus 
DCONFORMITY ase 
UPPER CHOUTEAU Siphonodelia isosticha-5 cooper q FB 
|| Seethognatnodus costotus costatus- Gnethesus delicatus 
LOWER. CHOUTEAU. \ A 9 3 cat 
) K19 
z 2 
S 1 Kies 
rs Spatnognothodus cf 5S robustus- S$ trigentatus 
ee eee Sipnenedelia. quadruplicata - $.crenuteta L-pruc 
2 rer} 
Fa 
a Siphonedella- Polygnatnus inernetus 
a 
2 v2 K 
= MIDDLE HANNIBAL Siphonodelia duplicata mu 
Patrognainus veriobilis - Spethognathogus plumulin 
Cowen HaNNieAl Sipnonodelle suicate Fs 
divi 
Zonation of the Avonian on the basis of conodonts, showing the relations 
ions of the Avon Gorge, and the North Crop, and also the relationship of the Yoredale strata in the upper part of the succession. A 
comparison is made with the conodont zones established in the Mississippi V 
ley and with the goniatite zones of Europe 
ip of the zones proposed in this paper to the coral/brachiopod 
