(os 
THE FAUNA OF THE RESIDUARY AUBURN 
CHERT OF LINCOLN COUNTY, MISSOURI* 
Ki. B. Pains. 
The silicified fossils which represent the fauna de- 
seribed in this paper occur in an exceedingly fine, porous, 
siliceous matrix, almost chalk-like in appearance. The 
masses of this siliceous material, which is evidently a 
decomposed chert, occur imbedded in a red residuary clay 
- exposed in the gutters by the roadside, a short distance 
east of Auburn, Lincoln County, Missouri. In 1896, Dr. 
Stuart Weller collected some of these masses and the fos- 
sils have been removed from them in the museum. 
Seventy species are here recognized in the fauna be- 
sides several species of crinoids (represented by the col- 
umns only), bryozoans and pelycopods too fragmentary to 
be referred to their proper genera. Of the species recog- 
nized, forty-three have been described, eleven are new and 
are here described for the first time, and sixteen are un- 
identified. Thirty-three of the old species are recorded in 
the Geological Survey of Minnesota, II.,as occurring 
in the Minnesota region, and of these eighteen occur in 
the Stones River group, sixteen in the Black River, four- 
teen in the Trenton, three in the Utica, and four in the 
Richmond. 
The presence of such species as Dalmanella subaequata, 
Orthis tricenaria, Zygospira nicolleti, and Lophospira 
perangulata in large numbers fixes the age of this forma- 
tion as low in the Mohawkian. Dalmanella testudinaria 
and Ctenodonta medialis, not hitherto recorded from be- 
low the Black River, are well represented and Hindia 
parva, Lichenaria typa, Carinaropsis phaleria, Carina- 
ropsis acuta, Lophospira owen, and Strosphostylus tea- 
tilus, not recorded elsewhere from below the Black River, 
* Presented by title to The Academy of Science of St. Louis, March 18, 
1907. 
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