gio THE JOURNAL OF GEOLOGY. 
2 E& 
. |e | S60) 2 |e 
g ee | &5 5 E 
rc) eae a a 
FI or Be = 5 
gate ee cre nian 
E as lass | 3 5 
== He | eee |e 5 
S) a yes]-t < es 
PTEROPODA. 
CHPWGHE congooggs b000 0008 60000000009 x x xg x 
JEIIDWIHIBs 0600 0660 C000 DOOb ADOC DDONNC SOD x x x x x 
CRINOIDEA. 
AB ONUADETUBUS 600906 000095008000 0000000 x 
ALN DOTTETUBIDS 095006800000005000000G06 XK 
(CGHIDOETURWS 600000000000c0060000000008 x x Ke Xe x 
DOF GIT SER Re te ea x x 
GCAMAUQDETUOUS sc0000 0000 000000b00000000 x Bs 
JENGHMCFURUS.s 000 0000 06040000564000 000000 x x 
SA HOORTUMOD c 000.0000 0900000900 00000009 x xe 
SApOHONMARHS 0000 sob 0 CO CDC OOR DOOD CONE OCR ee 
CORALS. 208 
AU GEIOGUS 200 DdOO DO GdODDNODEEOO GOOO0RD x x x x ? 
COWODON WB» 10000009 000000000000 0000 x x x x x 
Cyathophyllam «0.1.0. c cee vee e eens wveeee x XK x x x 
I(JMOPOPD oa00 0000 00H BD DbaDesoOnGO00500 x 
ILOILO PODOD 0000000000 000000000000 000C x 
MWIGEPQUBUD. go050 000005000 0000000000000C x x 
MWHEECOGNATIS o06009000900060000 000000000 Xe x x 
IEWWGGIEUS 5009 0000090060005 000D000000000 x 
SWHUOGOWUD 0520000000000 0000000000500 : x x x x X 
MOPBPHAOS coose pes caoonovggacocc000 D008 x x x x x 
TRILOBITA. 
IEAOCGMATOPIIS. o06500000000000000b00008 x vo 
JPY GPSUE. wo onc oo GDF AON ODO DA DONOOONES x x 
x 38 xX BG %% 
PEAVEY GH Minch Bae MIC AIRE ERRNO. OO50-8 5 GO 0 Db 
In the foregoing table it is seen that the genera, exclu- 
sive of those peculiar to the Chouteau, with but three excep- 
tions, may be divided into three groups. (1) Those common 
to the Chouteau and the east American faunas. (2) Those 
common to the Chouteau and the west American or Euro- 
pean faunas. (3) Those common ‘to all these faunas. It is 
important to observe that the genera of the last class are all 
older than those peculiar to only one of the two Middle Devo- 
nian provinces. As shown in the table they extend back into 
the Silurian time when the two areas were united. After the iso- 
lation of the two regions as distinct Devonian provinces, new 
genera originated, and those thus originating in the separate 
provinces were different. 
