Ulrich-Paleozoic Systems in Wisconsin. 
87 
note that in the 4 or 5 miles distance between Farwells Point on 
the north side of Lake Mendota and Pheasant Branch at the west 
extremity of the lake certain beds enter the section that are not 
present at Farwells Point or near-by in Maple Bluff. Namely, at 
Farwells Point only two feet of St. Lawrence limestone separate 
the Mendota dolomite from the underlying top of the Mazomanie 
sandstone. In the quarry at Pheasant Branch, on the contrary, 
the Mazomanie which outcrops on the lake shore is succeeded, first, 
by an undetermined but small thickness (less than 10 feet) of soft 
shaly and glauconitic sandstone beds, second, by 12 feet of St. 
Lawrence limestone, and, third, by at least 5 feet of yellow and 
purple calcareous sandy shale that not only has the lithological 
characters of the Lodi shale but also some of its characteristic fos¬ 
sils. Above this shale the section is not exposed for about 35 feet, 
when a three-foot ledge of coarse white and brownish sandstone 
that resembles the Jordan but more probably belongs at the base 
of the Oneota dolomite comes to the surface. The covered inter¬ 
val may be occupied by either the Madison sandstone or the Men¬ 
dota dolomite or by thin representatives of both, or, as seems the 
more probable, by Jordan sandstone only. In the near-by Leith 
well only one limestone (evidently the St. Lawrence) is found be¬ 
neath the Oneota. 
The Lodi shale member usually is fossiliferous, and its fauna, so 
far as known, is almost entirely confined to this member. As the 
commonest and most characteristic of its species we may cite 
Dikelocephalus minnesotensis, Saukia crassimarginata, S. lodensis, 
and Aglaspis harrandei. With these, and usually more abundantly 
than anything else, occur species of brachiopods provisionally 
identified with Westonia stoneana and W. aurora. 
St. Lawrence limestone or dolomite (as originally defined).—^As 
stated on a preceding page, some distinctive name is desirable for 
the bed of highly magnesian limestone that commonly underlies 
the Lodi shale member in Wisconsin, Minnesota, and probably also 
in northeastern Iowa. Further, as the name St. Lawrence lime¬ 
stone proved on visiting the type locality to have been based by 
Winchell on the very bed for which a name would now be a useful 
aid in describing the several divisions of the Trempealeau forma¬ 
tion it has seemed eminently proper to adopt Winchell’s term in 
the restricted sense in which it was originally used. There is no 
doubt whatever in my mind that the ‘ ‘ St. Lawrence limestone ’ ’ de¬ 
scribed by N. H. Winchell in 1874^® is the bed here referred to as 
