Originally published in 1889, this comprehensive study of sea urchins remains the standard reference work on the subject. Its author, Peter Martin Duncan, was a leading British naturalist of his day, and his meticulous classification system and detailed descriptions continue to be admired by scientists today. Whether you are a marine biologist, a zoologist, or just a lover of nature, this book is an essential addition to your library. This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work is in the "public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.