944 The American Naturalist. [November, 
volume, however, brings together everything essential that has ever 
been made out in regard to Amphioxus, so that zoologists will every- 
where feel grateful to Mr. Willey for placing in their hands this very 
useful summary of its life history. The work contains not alittle that 
is new, and some new figures not hitherto published. A very complete 
bibliography and index completes the volume. One hundred and 
thirty-three titles are comprised in the list of papers and works con- 
sulted in the preparation of the volume. If the other volumes in 
course of preparation by the professors in biology of Columbia Uni- 
versity are up to the high standard of the present one, that institution 
is to be congratulated upon the enterprise of those who have initiated 
the project.—R. 
Correlation Papers of the U. S. Geol. Survey: Archean 
and Algonkian.'— This memoir, written by Prof. C. R. Van Hise, 
is the seventh of the Correlation Papers series, and is, perhaps, one of 
the most important of that valuable set. The pre-Cambrian rocks of 
the United States and Canada, for convenience, are considered under 
the heads of seven districts, which are severally discussed in as many 
ehapters. Each chapter is prefaced with abstracts of all the articles 
pertaining to the subject considered, classified by dates, together with 
summaries of the conclusions which appear to be established. Chapter 
VIII summarizes the various successions proposed, suggests one, and 
discusses the principles of pre-Cambrian stratigraphy. The Archean 
is the basal complex of America. It has everywhere, if large areas 
are considered, an essential likeness. It consists mainly of granitic, 
gneissie and schistic rocks, among which are never found beds 
of indubitable clastics. When different kinds of rocks are asso- 
ciated, their structural relations are intricate, which, together 
with the crystalline schistose character of the rocks, the broken and 
distorted mineral constituents, and involuted foldings are evidences 
that these rocks have passed through repeated powerful dynamie 
movements. 
In regard to Algonkian stratigraphy, the writer accepts the struc- 
tural and lithological principles enunciated by Irving, Pumpelly and 
Dale. It remains to be demonstrated, however, to the satisfaction of 
most geologists that the formation termed Algonkian, is not a part of 
the Cambrian. 
* Bulletin of the Geological Survey, No. 86. eepe Peer Archean 
and Algonkian. By Charles R. Van Hise. Washington, 18 
—É 
