This is the largest species of sea pen encountered by divers in the northern Pacific. the short, slender branches of the stalk are white, as are the polyps.

"For each of the thirty-two currently recognized phyla, Invertebrates presents detailed classifications, revised taxonomic synopses, updated information on gene

"The third edition of Ecology and Classification of North American Freshwater Invertebrates continues the tradition of in-depth coverage of the biology, ecology

So much has to be crammed into today's biology courses that basic information on animal groups and their evolutionary origins is often left out. This is particu

Popular interest in the observation and study of freshwater invertebrates is increasing. This book meets the needs of this growing audience of naturalists, envi