A. Winchell on Drift Materials in Michigan. 337 
ensis Hall, Spirifera Marcyi Hall, Spirigera concentrica Brown, sp., 
Platyceras attenuatum Hall, Dalmania Boothi Green, sp., and 
; state, a great thickness of argillaceous and bituminous shales, 
oe destitute of fossils, but freighted with Kidney iron ore. Nod- 
, by some 
geologists, they might preferably be referred to the indigenous 
strata 
Still again, the well marked fossiliferous beds of the Marshall 
sandstone, lying next above the Huron shales, and outcropping 
along a belt still farther north, is represented by a series of 
enormous fragments resting over the non-fossiliferous upper por- 
tions and the Carboniferous limestone. The lower, or fossilifer- 
ous portions of this formation do not outcrop farther north 
than Moscow, in Hillsdale county, 
fossiliferous fragments led me for some time to suppose the 
actual outcrop must be in the immediate vicinity ; although I 
had found the non-fossiliferous Napoleon sandstone givbonie 
p o 
, rous other species. The fossiliferous layers 
Of the Marshall sandstone are decidedly fria safes ch that 
facies, due to local, if not to climatic causes, 
itself; but ey the contrary, we find the fauna of 
