VI Contents. 
(Jarboniferous Formations of Southwestern Iowa. 
Charles R. Keyes 346 
The Peneplain. R. S. Tarr 351 
Studies on an Interesting Hornblende, occurring in a 
Hornblende Gabbro, from Pavone, near Ivrea, Pied- 
mont, Italy. Frank R. Van Horn 370 
Ben Nevis, the Last Strongliold of the British Ice- 
Sheet. Warren Upham 375 
Review of Recent Geological Literature. — Mineral Resources of the 
Uuited States, 1896, David T. Day, 380.— Reconnaissance of the 
Gold Fields of Southern Alaska, with some Notes on General Geol- 
ogy, George F. Becker, 382.— Iowa Geological Survey. Admin- 
istrative Reports, 382.— Kalgoorlite, a New Telluride Mineral from 
Western Australia, E. F. Pittman, 383.— Catalogue of the Tertia- 
ry MoUusca in the Department of Geology, British Museum, (Nat. 
Hist.). Part I. The Australian Tertiary Mollusca, George F. 
Harris, 383.— VestAnafaltet: En Petrogenetisk Studie. (With an 
English Summary), Helge Backstrom, 385. 
Monthly Authors' Catalogue of American Geological Literature, 387. 
Correspondence, On Mr. Frank Leveretfs "Correlation of Moraines 
with Beaches on the Border of Lake Erie," J. W. Spencer, .393. 
Personal and Scientific News, 396. 
Index, 399. 
Errata for Vol. XX. 
Page 164, line 14, for "pot" read pool. 
Page 165, line 13, for "rbyolite" read hyalite. 
Page 334, line 9 from the bottom, for "tombidre'" read tourbikre. 
Page 410, line 8, erase, the comma after vote. 
Page 417, last line but one, for "deserve" read receive. 
Page 418, lino 5 from the bottom, for "Stopniow" read Spendiarow. 
Page 420, line 2 of small type, for " west side" read east side. 
Errata for Vol. XXI. 
Page 70, line 1, for "Fraser" read Frazer. 
Page 133, line 1, for "Tyrell" read Tyrrell. 
Page 133, line 25, for "1898" read 1897. 
Page 250, line 19 from the bottom, for "Nuclei" read Nucleus. 
Page 250. line 2 from the bottom, for "5th" read 4th. 
Page 328, line 10, in place of this line read ogists.) (Am. (ieol. vol. 21, pp. 2J3-219, 
Apr. 1898.) 
