48 Bulletin of Wisconsin Natural History Society. Vol. 1, No. 1. 
that he should have drawn the conclusions he did, and, as at the 
time of his investigations, the formation was considered of no 
special commercial miportance and was therefore not worked, and 
as the exposure was of a slight geographical area, being known at 
that time only from a very Hmited exposure near what was then 
the A'illage of Humboldt and a short distance above it on the Mil- 
waukee River, as well as of an exceedingly slight geological hori- 
zon, the exposure at that time being but a few feet vertical- 
ly, not" exceeding more than three or four feet at most, 
for a very short distance along the margin of the river, 
where the}- are very deeply overlaid by the drift, there was 
probably a reasonable excuse for the conclusions drawn. In writ- 
ing of the state of preservation of the organic remains he^ how- 
ever, says : "The upper limestone and shales which imperfectly 
represent the Upper Helderberg and a part of the Hamilton 
groups, through nearlv all of the rocks of this age there is much 
iron p} ritcs and, owing to the decomposition of this mineral, the 
shells are mostly destroyed, leaving only casts of the interior." 
While this is the case with many of the fossils collected throughout 
the formation, in this locality the specimens from the upper layers 
are quite generally in a very perfect state of preservation in most 
cases not only the shells, but the very fine and delicate markings 
peculiar to each species being perfectly preserved. In the list of 
fossils given in the- same report described from the various forma- 
tions in the state, or identified with species described from other 
states, only four species are given from the formation, these are 
simply referred to the Devonian, no' reference being made to the 
group, and no species whatever being given as from the Helder- 
berg. 
The late I. A. Lapham in his "Report of Progress and Results" 
for the year 1874, made but a very slight reference to the Devonian 
formation, and none whatever tO' the group. Dr. O. M; Wright, 
who was the chief geologist of the State of Wisconsin during the 
year 1875. ^1"^ annual report for that year discussed to a con- 
siderable extent the formations that had previously l^een recog- 
nized as Upper Helderberg and Hamilton, and dissenting from all 
previous views on the subject, principally on account of the non- 
representation of formations that arc wanting in this locality, as 
well as on erroneous identification of the organic remains and, as 
he says, chiefly on stratigraphical evidence, maintains that the 
formation under consideration is the water-lime group of the 
Lower Helderberg, of the organic remains collected near Hum- 
boldt by himself, he quotes Orthis plicafa, now Spirifer Vannxmni, 
Avicula nigosa. and a species of TentaciiHtcs, he also says that 
Lcpcrditia alta, a still more important characteristic fossil, has also 
