72 Wisconsin Academy of Sciences, Arts, and Letters. 
grayish yellow irregularly bedded magnesian mudstones and brown¬ 
ish dolomite aggregating some 50 to 60 feet in thickness. On weath¬ 
ering the upper half or more of these beds shows more or less 
of earthy chert in nodules and uneven plates. The bluish gray 
lower third contains few fossils, those found being of a diplograptid 
(? Mesograptus sp.) Dictyonema sp. and broadly branching car¬ 
bonaceous films supposed to belong to some marine plant. The lat¬ 
ter two seem indistinguishable from specimens found in the lower 
part of the Cataract formation in Ontario. The cherty upper beds 
contain a more varied though not abundant fauna. Among them 
I have provisionally identified the following: Streptelasma aft. 
divaricans and radicans, Streptelasma aft. rnstica, Lindstromia sp., 
Halysites sp., Favosites sp., Anaphragma aff. mirahile, Phaenopora 
ensiformis, Phaenopora cf. fimhriata, Nematopora aff. delicatula, 
Helopora cf. fragilis, Bhinopora sp.. Lingula sp., Pholidops sp., 
Leptaena cf. rugosa, Plectorthis cf. whitfieldi, Dalmanella cf. edge- 
woodensis, Strophonella cf. patent a, Atrypa praemargmalis, Zy- 
gospira putilla, Tentaculites cf. oswegoensis, Orthoceras cf. sociale, 
Proetus sp., Calymene sp. Obviously this fauna is decidedly post- 
Richmond ; and it is as clearly older than Clinton. Evidently then 
it falls into some part of the intermediate Upper Medina stage in 
which the Edgewood formation of Missouri is probably a nearer 
contemporary than the Cataract of Ontario. 
Lithologically the formation is so different from the Edgewood 
that it is thought unwise to employ that term for the beds under 
consideration, especially as there is some doubt as to their strict 
equivalence. According I propose the name Burroughs dolomite. 
The same beds are indicated, though mainly by debris, in the 
mounds in southwestern Wisconsin. Hitherto they have been 
classed with the Niagaran dolomite that caps these and similar 
mounds in northwestern Illinois and northeastern Iowa. 
The Names Trempealeau Formation, St. Lawrence Limestone 
OR Formation, and Jordan Sandstone 
Three facts have been mainly responsible for the proposal to 
substitute the new name Trempealeau formation for the series of 
beds to which I have previously applied the term St. Lawrence. 
First, the outcrops in St. Lawrence township, Minnesota, for which 
N. H. Winchell originally proposed the name St. Lawrence lime¬ 
stone is so limited and its relations to overlying and underlying 
