W. J. lie Gee — Geology of the Mississippi Valley. 353 



plants or fucoid remains. South of the Bay, at Valencia Lighthouse, 

 are tracks, suggested by Mr. W. Hellier Baily to be those of a Crusta- 

 cean. They may, however, be a track made by a fish, as I have 

 seen somewhat similar tracks made by the grey gurnets on the sand 

 floor of their tank at the Crystal Palace, Sydenham. The plants at 

 Glanroe, west of Coomasahara, are well preserved and are perfectly 

 distinct, and Mr. Baily's diagrams show that some of them are 

 indistinguishable from those called Sagenaria Veltheimiana, found in 

 the "Old Bed Sandstone" at Tallow Bridge, co. Waterford, and at 

 Kiltorcan, co. Kilkenny. 



Note in Press. — Since this paper was read Mr. Baily has found 

 similar " Kiltorcan type " plants in other localities in the " Glen- 

 gariff grits." 



III. — Notes on the Surface Geology of a Part of the 

 Mississippi Yalley. 



By W. J. McGee, etc., etc., 

 of Farley, Iowa. 



A SOMEWHAT detailed description of the surface deposits of 

 North-eastern Iowa, with references to observations of a 

 similar nature in other localities, and some general conclusions, was 

 read by the author before the American Association at its St. Louis 

 meeting, and is printed in the Proceedings for 1878. 1 Since the 

 preparation of that paper additional observations have been made in 

 the same region ; and some other localities, mainly in the State of 

 Illinois, have been visited. A general section has been made across 

 the northern portion of this State, from the Mississippi on the west 

 to Lake Michigan on the east, at about 42° N. lat. A like section 

 has been made the greater part of the length of the State from north 

 to south, at about long. 89° W. from Greenwich. The data employed 

 in the construction of these sections were chiefly derived from 

 personal observations on the surface, in channels of erosion, and in 

 artificial excavations ; but use has also been made of the observa- 

 tions of other persons, collected by means of extensive inquiries 

 from, and correspondence with, local geologists and others. In Iowa, 

 a formation, believed to be distinct from any previously described, 

 has been discovered, and a rather anomalous distribution of the 

 member considered to be the equivalent of the loess has been brought 

 to light. Several dsar, which seem to be homologous with those of 

 Scandinavia, have also been traced over some distance. 



Advantage has been taken of the wide circulation of the Geolo- 

 gical Magazine among workers in this department of geology, to 

 lay before them a brief resume of these observations, in advance of 

 any more comprehensive publication. The division of the superficial 

 deposits into separate formations or members, adopted in the paper 

 just mentioned, will be adhered to, but the description of each will 

 be so modified as to apply to the wider area since examined ; and 



1 The full title of the paper is, " On the Complete Series of Superficial Forma- 

 tions in North-eastern Iowa, by W. J. McGee." 



DECADE II. VOL. VI. — NO. VIII, 23 



