Book ReviewsThe Earth Sciences Principles of Invertebrate Paleontology. 2nd ed. of Invertebrate Paleontology. Robert R. Shrock and William H. Twenhofel. New York-London: McGraw-Hill, 1953. 816 pp. Illus. $12.00 + See all authors and affiliations Science 17 Apr 1953:Vol. 117, Issue 3042, pp. 431DOI: 10.1126/science.117.3042.431 G. WINSTON SINCLAIRFind this author on Google Scholar Find this author on PubMed Search for this author on this site Article Info & Metrics eLetters PDF This is a PDF-only article. The first page of the PDF of this article appears below.