Recent Publications. 431 
ried Trenton limestone boulders up 1,100 feel in a distance of 20 miles 
southward on the Archean highlands. Approaching the St. Lawrence, 
the striatum is found to be much influenced b\ minor topographic 
forms of valleys and hills. Till is spread over the whole region, cover- 
ingtoa greater or less thick ttess the rounded Archean hills; and only 
along the stream valleys is ii concealed bj gravels, sands and clays, of 
ilic modified drift and <it' later alluvial origin. The end (if the Glacial 
period was attended bj a depression of this part of the continent about 
600 feet below its present elevation, as shown by terraces and deltas of 
fossiliferous stratified marine clays and sands, forming portions of the 
modified drift, which rest on the slopes of the till along the river val- 
leys. 
Other reports in this volume are by L. W. BAILEY and W. MclNNES, 
on the counties of Temiscouata and Rimouski, in the province of Que- 
bec, and on adjoining areas in New Brunswick and Maine (28 pages); by 
Hugh Fletcher, on the counties of Pictouand Colchester, Nova Scotia 
(193 pages); by II. P. II. Brumell, on natural gas and petroleum in On- 
tario (94 pages); by G. C. Hoffman, on the chemical work of the survej 
(72 pages); and by E. D. [NGALL, on mineral statistics and mines, for 
1890 and 1891 (together 401 pages). 
RECENT PUBLICATIONS. 
/. Government and state Reports. 
Annual Report of the Hoard of Regents of the Smithsonian Institu- 
tion, 1891, contains: Some applications of physics and mathematics 
to geology, C. -Chree; Origin of the rock pressure of natural gas in the 
Trenton limestone of Ohio and Indiana. Edward Orton; Geysers, \Y. II. 
Weed: The Gulf Stream. Alexander Agassiz; On the absolute measure 
of hardness. F. Auerbach; The How of solids, or the behavior of solids 
under high pressure. Win. Hallock. 
Bulletin of the United States Geological Survey, No. 106, The Colo- 
rado formation and its invertebrate fauna. T. W. Stanton. 
Geological Survej of Alabama: Reporl on the Coal Measures of 
Blount mountain, with map and sections, h.\ A. M. Gibson. 8vo., pp. 
[-80, 1893. 
Iowa Geological Survey, vol. 2: Coal deposits of Iowa, bj C. R. Keyes, 
536 pages, 18 plates. 1894. 
Eighteenth Annual Report of the State Geologist of Indiana, con- 
tains: (ntroductory, S. S. Gorbj ; < leologj of Noble county, C. R. Dryer; 
Ploraof Noble county, W. B. Van Gorder; Reporl upon the geologj of 
Lagrange county, C. R. Dryer; The drift of the Wabash-Erie region, 
< !. It. Dryer: Report of the inspector of mines. Thomas McQuade; Re 
port of the state supervisor of oils. N. .1 Hyde; Reporl of the state 
