The author is first and foremost indebted to Mr. and Mrs. Cornelius Crane for their unfailing interest in the preparation of this field guide, and to members of the Museum staff who collaborated to edit and produce it. Among these were Norman D. Harris, Director of Education, Gilbert E. Merrill and Chan Waldron of the Education Department, Miss Caroline Harrison, Director of Public Relations, and Mrs. Christina Lopes and Mrs. Margaret Jordan of her department. Invaluable also in preparation of the manuscript was the careful final editing of Miss Helen Phillips, Houghton Mifflin Company.

Especially is the author grateful to the following for advice and comment on various chapters: Clifford S. Chater, Assistant Professor, Entomology and Plant Pathology, Waltham Field Station; Dr. Norman A. Preble, Mammalogist, Northeastern University; J. Phillip Schafer, Geologist, U. S. Geological Survey; Colonel E. S. Clark, Curator of Marine Life, Peabody Museum of Salem, and Dr. Stuart K. Harris, Department of Botany, Boston University.

L.B.W.