146 The American Geologist. September, 
brinus, Eunella lincklaeni, Lingula complanata, L. maida, L. 
spatulata, L. paliforrms, Orbiculoidea lodicnsis, OvthotJictes 
arctistriata, Pliolidostrophia iowaensis, Schizophoria striatula, 
Stroplieodonta demissa and 6". perplana. This may seem a 
formidable list, but on careful scrutiny it proves of little con- 
sequence, for no paleontologist would pay much attention to 
species of Lingula, Craniclla, Orbiculoidea, Chonetes, Atrypa 
and Orthothetes, or to Schizophoria striatula, Stroplieodonta 
demissa, S. perplana and Cyrtina hamiltonensis for the deter- 
mination of faunal differentiation. Eliminating these there 
remain Spirifer cousobrinus, Eunella Hnckacni and Pliolidos- 
trophia. Against their presence, note the absence at Milwau- 
kee (also Iowa) of nearly all the characteristic Xew York 
Hamilton species, such as Spirifer granulosus, S. mucronatus, 
S. divaricatus, Tropidoleptus, Vitulina, Rhipidomella, Stro- 
plieodonta concava, etc. On the other hand, note the presence 
at Milwaukee of the characteristic western species, as an 
abundance of Schizophoria, Spirifer pennatus, S. subvaricos- 
us, Cyrtina with plicated fold and sinus, and Dielasma calvini. 
It should also be noted here that of the "j^ species common to 
the western and eastern regions, no fewer than 23 also occur in 
the Upper Devonic of New York. This fact indicates that 
either some of the identifications are not accurate or that the 
Milwaukee Devonic includes not only a part of the Hamilton 
but also a part of the Portage of New York, and also that the 
former region has probably received migrants from the east. 
The writer thinks the latter view the correct one as it has been 
demonstrated by Clarke, Williams and Calvin that the High 
Point Chemung faunule is a migration of a part of the Lime 
Creek, Iowa, Upper Devonic. These higher beds of the Upper 
Devonic have been removed in the Milwaukee-Chicago area* 
but in Michigan are present as the Antrim formation. The 
characteristic "Black shale" phase of the Upper Devonic ex- 
tending from New York to eastern Michigan is still present 
in northwestern Michigan but is not known in northern Il- 
linois, Iowa or Missouri. 
Contrasting the Milwaukee fauna with that of Thedford in 
western Ontario, quite a different development is seen. The 
* See Wrller, Jour. Geo], vii, 1899, p. 4-S3. It is here shown that Devonic 
and probably Upper Devonic fossils are found in crevices of the Niagara dolo- 
mites fifteen miles west of Chicago at the Elmhnrst quarries, Illinois. 
Also see Folio No. 81, U. S. Geol. Surr., 1903, p. 3, by Alden. 
