Correspondence. 351 
Glaciation: Its relations to the Lackawanna — Wyoming region. A lec- 
ture delivered before the Lackawanna Institute July 3,1886. John C. Bran- 
ner. 
o. Foreign Publications. 
Nouvelles recherches sur Torigine du nom d'Amerique, par Jules ilar 
ecu. 8oc. de Geog., Paris, 1888. 
Sur les cartes geologiques a I'occasion du"Mapoteca geologica Amera- 
cana,"par Jules Marcou. Ex. des Mem. de la societe rf' emul'ition de iJoubs, 
April, 1887. 
On the mammaliferous gravel at Ellougbton in the Hamber valley. 
Report on the buried cliff at Sewerby, near Bridlington on the larger 
boulders of Flambro Head, part 1. The last three are by Mr. G. W. 
Lamplugh and are extracted from the Proceedings of the VorksJiire Geologi- 
cal and Polytechnic Society. Vol. ix., 1887. 
Report on the geological features of the Mackay district, Queensland, 
Townsville, November, 1887. By Robert L. Jack. Ten pages folio, -with 
two maps. 
Anniversary address of the president of the Roy. Soc. N. S. W., delivered 
May 2, 1888. By C. S. Wilkinson F. G. S. ; treats of New South Wales— 
a field for geological investigation. 
Ueber einige mikroskopisch-chemische Reaktionen ; von A. Streng, in 
Giessen . Neues Jahrb^ 1888, Bd. II. 
CORRESPONDENCE. 
Prof. N. H . Winchell has referred to the writer two small specimens 
of quartzite sent to him by Mr. Vernon Bailey, who says: "I broke them 
from rocks along the road from Niobrara to O'Neil, Neb. It was the 
only kind of rock seen between the places, and this was abundant, as 
large angular bowlders. Some hills near the Niobrara river were thickly 
strewn with them. The country where it was found is all sand and peb- 
bles — no bowlders of any other kind. Evidently it is of the Sioux Falls 
or Pipestone formation, though I have never seen any of just the color. 
Perhaps you can tell near where it came from." 
The specimens are of a pale yellowish green color, resinous lustre, and 
fracture like obsidian. These characters do not agree at all with the 
Sioux Falls quartzite, but they do agree closely with a Tertiary quartzite 
seen at Valentine, Nebraska. A small weathered surface on one speci- 
men indicates that the rock weathei'S gray, which also agrees with the 
Valentine quartzite. 
The region between Niobrara and O'Neil is colored green for Cretace- 
ous in the maps of the U. S. Geologists, and the occurrence then of a Ter- 
tiary stratum scattered over the hills probably indicates a former exten- 
sion of the Tertiary to the eastward some seventy-five miles, the softer 
portions having been eroded away, leaving the hard quartzite as a witness 
of the previous existence of the Tertiary in that region. The abundance 
