Magnacarina gen. nov. from Mexico is described. Hapalopus aldanus West, 2000 from Nayarit, is transferred to the new genus with an emended diagnosis creating the new combination Magnacarina aldana comb. nov. Three new species are described: Magnacarina moderata Locht, Mendoza & Medina sp. nov. from Nayarit and Sinaloa; Magnacarina primaverensis Mendoza & Locht sp. nov. and Magnacarina cancer Mendoza & Locht sp. nov., both from Jalisco. Magnacarina gen. nov. is characterized by an unusual bifid palpal bulb, and has a primary projection located in the central area of the palpal bulb and directed retrolaterally; this projection possesses the prolateral superior and retrolateral keels. Next to the primary projection is a secondary projection, which may be short or long, ending in the prolateral inferior and apical keel surrounding the sperm pore. This secondary projection may have prolateral accessory keels and is diagnosed by possessing a nodule of inwardly curled megaspines, located in the basal ventro-retrolateral region of metatarsi I in adult males. Additionally, male tibiae I possess three apophyses. Females of Magnacarina gen. nov. have a single reduced and strongly sclerotized spermatheca, with an apical lobe projecting ventrally, and with a uterus externus that is longer and wider than the spermatheca.
The theraphosine genus Hemirrhagus Simon 1903 is revised based on the examination of the type specimens and additional material collected in Mexico. Eight species were redescribed and illustrated. The males of Hemirrhagus ocellatus, Hemirrhagus papalotl, and Hemirrhagus stygius, formerly unknown, are described for the first time. Five new species were recognized and are newly described and illustrated. Hence, Hemirrhagus comprises 21 valid species, all endemic to Mexico. All species are keyed and mapped. New taxonomic features are included in the descriptions and different types of stridulatory organs are described for the first time for the genus. It is reported for the first time that Hemirrhagus is the only known Theraphosinae that lays fixed egg-sacs. Hemirrhagus embolulatus sp. nov. is described as the only known Hemirrhagus that possesses embolus keels present in other Theraphosinae genera. Information on species habitat and reproduction are included. © 2014 The Linnean Society of London