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One of the paired saccular respiratory organs found in some arachnids, such as scorpions and spiders, consisting of several parallel membranous folds arranged like the pages in a book.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
the respiratory organ of many arachnids, composed of thin, paperlike layers of tissue.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
The breathing organ of scorpions, spiders, and some other arachnids. It consists of membranes arranged in several parallel folds like the pages of a book.
The American Heritage® Student Science Dictionary, Second Edition. Copyright © 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.