3o8 The American Geologist. November. 1902 
regular in most exposures, yet .the sandy content of the young- 
er formation makes it readily distinguishable. There was evi- 
dently a change to returning marine conditions for unlike the 
fauna of the lower formation which has no brachiopods, the 
Saint Louis fauna comprises Brachipoda only, as far as known 
to me. 
We are indebted to A. D. Bicknell of Humboldt for the 
discovery of fossils in the Saint Louis formation at that place, 
and though MacBride (op. cit., p. 127.) says "no fossils are 
discoverable to guide us in our researches" yet the evidence at 
hand praves how risky it is to base such a statement on a sed- 
imentary rock. The locality where these were found is not 
new and is marked on the geologic map. In ^Ir. Peckham's 
quarry one-half mile south of the depot, near the M. & St. L. 
Ry. track, I collected many specimens comprising the follow- 
ing species: Eumetria marcyi SIiiiiii. (E. verneuiliana H.), 
Spirifer increbescens Hall, Athyris (Siminula) cf. subquadra- 
ta Hall, Athyris incrassata Hall, and Terebratula (Dielasma) 
formosa Hall. These fossils are abundant in certain strata of 
granular limejstone and a superjacent shale though good spec- 
imens are not easily obtained. They lie on a reef-like elevation 
which is probably due to a mound of" Kindprhook limestone 
beneath it. The strata are mainly of the common sandy tex- 
ture, but with some irregular purely limestone or "lithograph- 
ic" layers. I did not observe to which part of the formation 
they belong. 
Correlation of strata lying unevenly and seen in few small 
exposures, offers some difficulty, but the gross reference to one 
formation of several outcrops on the, East Des Moines and be- 
low the rivers' confluence and again westward along the West 
river to and beyond the county boundary, is probably correct. 
Yet other exposures than those heretofore mentioned or 
mapped were incidentally met with about Humboldt and since 
occasion did not permit me to trace the fdrmation through- 
out, it is assumed that the obtainable evidence is rather incom- 
pletely gathered as yet and the use of the name Saint Louis 
formation in the same sense as MacBride has done is not there- 
fore meant to be conclusive. 
The fossil fauna which is collected from the Saint Louis at 
Humboldt is seen to be nearlv the same as that "which was re- 
