Gertsch, Willis John, 1906-2005-10-062005-10-061979http://hdl.handle.net/2246/542532 p. : ill., maps ; 26 cm.Includes bibliographical references (p. 31-32)."The Argentinean spider Mecicobothrium thorelli Holmberg is redescribed on the basis of the first specimens to be discovered since the long lost holotype was collected in 1881; the female is described for the first time. The female of the Californian species Megahexura fulva (Chamberlin) is redescribed and the male described for the first time. Hexura picea Simon from Washington and Oregon is redescribed and a new species, Hexura rothi, is described from Oregon. A new genus, Hexurella, is established for four new species: H. pinea and H. apachea from Arizona, H. rupicola from California, and H. encina from Baja California. The presence of an elongated, cymbium-shaped tarsus surrounding the male palpal bulb is suggested to be synapomorphic for the family. Evidence from the structure of the tarsal organ is used to support the previous rejection of a hypothesized sister-group relationship between the Mecicobothriidae and Antrodiaetidae in favor of one between the Mecicobothriidae and Dipluridae"--P. [1].14589381 bytesapplication/pdfen-USQL1 .A436 no.2687, 1979MecicobothriidaeSpiders -- West (U.S.)Spiders -- Mexico -- Baja California (Peninsula)Spiders -- ArgentinaArachnida -- West (U.S.)Arachnida -- Mexico -- Baja California (Peninsula)Arachnida -- Argentinatext