III 
CONTENTS. 
JULY NUMBER. 
New and little known Invertebrata from the Neoco- 
mian of Kansas. F. W. Cragin. [Plate I.] 1 
Causes aud Conditions of Glaciation. Warren Up- 
HAM 12 
The Present Conditions of the Earth's Interior as 
viewed from the standpoint of the Nebular Hy- 
pothesis. W. H. Seamon 20 
Notes on some localities of Mesozoic and Paleozoic in 
Shasta county, California. H. W. Fairbanks. . . 25 
On a Recent Diamond Find in Wisconsin and on the 
probable source of this and other Wisconsin Dia- 
monds. W. H. Hobbs. [Illustrated.] 31 
Differential Faults. W. H. Hobbs 35 
The Early Stages of Bactrites. J. M. Clarke. [Plate 
II. ] 37 
Editorial Comment. — Death of Mr. Wm. Pengelly, 43. — The Columbian 
Exposition: Exhibits of the Geology of Canada, 44; and Crystal- 
line Rocks, 46. 
Review of Recent Geological Literature. — Report on Irrigation, R. J. 
Hinton, 48.— The Colorado formation and its Invertebrate Fauna, 
T. W. Stanton, 51. — A Geological Reconnoissance in central Wash- 
ington, I. C.Russell,, 51.— Work and Scope of the Iowa Geological 
Survey, C. R. Keyes, 52. — Summary of Progress in Mineralogy and 
Petrography in 1893, W. S. Baylet, 52. — Orbicular Granite from 
Rhode Island, J. P. Kemp, 53. — Argyrodite and a new Sulphostan- 
nate of Silver from Bolivia, S. L. Penfield, 53. — The ejected 
blocks of Monte Somma, H. J. Johnston-Lavis, 53. — Svenskaklot- 
graniter, H. Backstrom, 53. — Rensselaer Grit Plateau, New York, 
T.N. Dale, 54. 
Recent Publications, 55. 
Correspondence. — Reply to statements in Prof. Tarrs "Lake Cayuga a 
Rock Basin, F.W. Simonds," 58. — The Niagara Gorge as a Measure 
of the Postglacial period, Warren Upham, 62. 
Personal and Scientific News, 65. 
AUGUST NUMBER. 
The Madison Type of Drumlins. Warren Upham. 
[Plate III.] 60 
Notes on the Geology of the Rocky Mountains be- 
tween the Saskatchewan and the Athabasca. A. 
P. Coleman 83 
Notes on the Geology of the Coast Rauges of Califor- 
nia. H. W. Turner and T. W. Stanton ( .>'J 
Growth of Knowledge concerning the Texas Creta- 
ceous. Jules Marcou 98 
z^ e> 5 ^ 
