A Taxonomic Study Of The Genus Arisaema In North America

Author : Robert Allen Cooley
Publisher : Forgotten Books
ISBN 13 : 9781390518559
Total Pages : 164 pages
Book Rating : 4.5/5 (185 download)

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Download or read book The Argasidae of North America, Central America and Cuba (Classic Reprint) written by Robert Allen Cooley and published by Forgotten Books. This book was released on 2018-09-08 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: Excerpt from The Argasidae of North America, Central America and Cuba The taxonomic study of the Argasidae has been beset with difficult problems, some of which are still unsolved. The principal difficulty has been and still is the lack of adequate generic characters. Some of the earlier species were described from very few specimens and frequently with very little knowl edge Oi their biologies. By 1908, Neumann and Nuttall had notably improved the situation by better generic definitions and the use of new specific characters. Both retained as genera only Argas and Ornithodoros. In 1912 Banks added the genus Otobius, and in 1942 Antricola was added by the authors. In 1908 only some twenty species were known. Now in North America alone there are at least twenty-five species and about thirty new species have been described from other countries. The characters exhibited by these new species have served to clarify certain of the taxonomic problems; they have made others more confusing. Some specific distinctions have found corrobora tive support in the biologies. With the increasing number of new species, it has become more and more difficult to separate Arga; and Ornithodoros and we have found it necessary to change the previous conceptions of these genera. However, no genera have been synonymized. It is probable that subsequent workers will find Others necessary but it is earnestly hoped that none will be erected until reliable generic criteria have been clearly established. The present names serve the purpose and should be changed only for permanent reasons. In a previous paper1 the senior author emphasized the importance of variation within species. This occurs principally in the ornamentation, and the morphology is reasonably constant. In the Argasidae it is perhaps too early to evaluate fully the variation within species, but at least it is evident that it is of little importance in the genus Ornithodoros. Ornamentation is absent in the known species of the Argasidae except in Ornithodoros coriaceus. Where confusion has arisen in specific identities, it has been due largely to overlooking characters in the mammillae and hypostome, some Of which are not very easily detected, and the very distinct ones found in the larval stage which heretofore has not been thoroughly studied. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.