Richmond Group of Cincinnati Anticline. — Focrstc. 361 
of local development. The great variety of closely related 
forms of Plectortliis in the Lorraine, near Cincinnati, suggests 
that these species were largely differentiated in the area under 
consideration. This is also true of various forms of Zygospira, 
DaluiancUa, and Platystrophia in various parts of the Cincin- 
nati series. The various forms belonging to the group of 
Strophomcna rngosa, which occur in the Richmond series, were 
also probably differentiated in part in the area in question. 
They .show variations sufficiently distinct to warrant specific 
names, but thev are connected bv numerous intermediate forms. 
AN OLD PLATTE CHANNEL. 
By G. E. CoNDRA, Universitj- of Nebraska. 
The region considered in this paper is a shallow valley some 
twenty-eight miles long and six to eight miles wide extending 
across Saunders county from northwest to southeast. The 
nature of this country with its rich agricultural resources is 
slowly coming to be better understood by the prosperous resi- 
dents. As yet, the region has not been named. To the south, 
about Wahoo and Mead, it is by some erroneously called the 
Wahoo valley. To the north, near Morse Bluff and Cedar 
Blufifs,it is quite generally confused with the Sand creek val- 
ley. This incorrect use of terms is due to the fact that Wahoo 
creek, and Sand creek, a trilmtary of the former, have cut a 
shallow trough in and along the western side of the nameless 
valley. The name Wahoo does not properly apply to Ijoth 
troughs ; while such usage is not general, the name Wahoo 
should be restricted in use so that it will stand for the valley 
produced by the creek of that name. The same might be said 
of the use of the term Sand creek. It does not seem best to 
propose the names Greater Wahoo and Lesser Wahoo. A name 
that indicates occupation by an Indian tribe or stands for ef- 
fective service by some geologist should be selected. The 
writer prefers the latter, and at the suggestion of professor 
E. H. Boohour, state geologist, herein proposes the name "Todd 
valley" in honor of professor J. E. Todd of Vermilion, South 
Dakota, who has given much time to a study of the drift of 
this localitv. 
