REVIEWS 609 
Types of Sedimentary Overlap. By AMADEUS W. GRABAU. (Bulle- 
tin of the Geological Society of America, Vol. XVII, pp. 567- 
636.) Rochester, N. Y., 1906. 
The two main types of progressive sedimentary overlap are the marine, 
in which successive beds overlap toward the source of supply, and the 
non-marine, in which they overlap progressively away from the source of 
supply. Phenomena of overlap are described in detail, and the principles 
deduced from them are applied to the basal Paleozoic series, the basal 
Mesozoic series, the Devonian Black Shale problem, Saint Peter sandstone, 
Dakota sandstone, the Chemung-Catskill, Pocono, Mauch Chunk, Potts- 
ville, and other examples. The author has reached the conclusion that 
the Black Shale of the southern Appalachians is Mississippian. 
C. W. W. 
Interglacial Periods in Canada. By A. P. CoLEMAN. Imprenta y 
fototipia de la Secretaria de Fomento, México. Callején de 
Betlemitas numero 8, 1906. 
In this paper, which was read before the Mexican meeting of the 
Geological Congress (1906), the author shows ‘‘that extensive interglacial 
beds of at least three ages occur in Canada, the oldest in British Columbia 
and Alberta; two later ones, probably between the Illinoian and Iowan, 
and the Iowan and Wisconsin ice ages, in southern and northern Ontario. 
Extensive interglacial periods have not yet been disclosed in eastern Canada, 
though an interesting lignite bed in Cape Breton island is probably inter- 
glacial. The most thoroughly studied interglacial formation, that of 
Toronto, has furnished a large flora and fauna showing temperate condi- 
tions.” C2 W..W. 
The Shelburne and South Bend Meteorites. By OLIVER CUMMINGS. 
FARRINGTON. (Publication No. 109, Field Columbian Museum 
Geological Series, Vol. III, No. 2. Pp. 23, 18 plates. Chicago, 
1906.) 
The Shelburne, Ont., meteorite is a stony meteorite consisting of 
enstatite, chrysolite, and subordinate troilite and nickel—iron. The South 
Bend, Ind., meteorite consists of 78 per cent. chrysolite and 21 per cent. 
nickel-iron. The fall of the former was observed. 
C. W: W. 
