Two new species of Aphonopelma from the Mojave Desert are described, A. joshua and A . mojave . Four nominal species, Aphonopelma iodium (A. iodius), A . melanium (A . melanius), A. angusi , A . nevadanum, described from the Mojave Desert and the Great Basin are treated as a single species; Aphonopelma iodium (Chamberlin 1939) is proposed as the species name since it is one of two possible senior synonyms (the other, A . melanium (A . melanius) in the same publication) and is the specific name of the first Theraphosidae to be described from the Mojave Desert ; A. iodium is redescribed. Generic, subgeneric, and specific characters previously used to separate Aphonopelma are reviewed . Aphonopelma is redefined ; Clavopelma is removed from the synonymy of Aphonopelma . The status of the following eight species described prior to 1939 with type localities either in the United States or in Baja, Californi a is discussed : Aphonopelma californica, A . leiogaster (Doleschall), A . steindachneri (Ausserer), A. rusticum , A . marxi, A . helluo (Simon), A. rileyi (Marx), and A. pseudoroseum (Strand). Aphonopelma steindachneri , A . rusticum, A . marxi, and A . helluo are considered as valid species ; A . californica, A. leiogaster, A . rileyi, and A. pseudoroseum are considered as nomina dubia.