The Galena and 3Iaquoketa Series. — Sardeson. 23 
others. The third and uppernidst one was not then exposed 
there, and was not des(»ribed as different from the exposed 
portion, — which it certain]}^ is, — Init was included within the 
limits of the Maquoketa, as a matter of course. Strictly in 
accord with the letter of Mr. White's definition, three forma- 
tions should be included in the Maquoketa, but the middle 
one only was described by him. I propose, therefore, to in- 
clude all three under the name of Maquoketa (Hudson) series 
and to call the middle one Maquoketa formation. Otherwise 
the term might be rejected, as Jos. F. James has suggested.* 
The Galena series has been long since divided into two for- 
mations, the "Trenton proper," or Beloit formation, and the 
Galena formation. The distinction was at first based on the 
lithologi(;al phenomena, the lower formation having thinner, 
more compact strata, the upper, thick porous ones ; but this 
difference, which is best recognizable in the ''lead region," is 
not quite satisfactory, since local alteration of the rock has 
produced the typical Galena facies in the top of the Beloit 
formation, or again, the base of the former is little changed 
like the latter. A faunal distinction is needed in addition, 
and one is easily found. Taking the divisions as recognized 
b}^ Prof. T. C. Charaberlin, in southern Wisconsin, the Beloit 
formation is the zone of Orthis siiboiquata Con., (O. perveta 
Con., etc.), and the Galena is the zone of Receptacuh'tes oweni 
H, The Galena, as defined in that way, does not include the 
transition bed (number 10, see diagram, p. 24), and the same 
not being properly included in the Maquoketa formation, I 
have placed it as a sepai'ate formation, as part of the Maquo- 
keta series. The Maquoketa series may now be divided ex- 
clusive of the Transition formation, into two formations of 
which the lower is the Maquoketa formation, the upper the 
WykotF formation, as I previously designated it in Minnesota, 
and the two represent, so far as I know, what authors have 
now and then alluded to as upper and lower Maquoketa, re- 
spectively. The relations of the five formations are shown in 
the diagram on the next page. 
The division line by which the two chief groups, the (ralena 
series and Maquoketa series are divided, is only in a small 
degree more constant and distinct than those between the des- 
* American Geologist, vol. v, p. 335, 1890. 
