|すべての著者/寄与者：||Edmund D Brodie (Jr.)|
|注記：||Fig. 1.-Standards used to analyze melanophore pigmentation within the dorsal stripe (black-in-stripe).
Fig. 9.-Range map of Plethodon vandykei.
Fig. 10.-Range map of Plethodon larselli.
Fig. 11.-Range map of Plethodon vehiculum.
Fig. 12.-Range map of Plethodon dunni.
Fig. 13.-Range map of Plethodon gordoni sp. nov.
Fig. 14.-Habitat at Dinner Creek, the type locality of P. gordoni.
Fig. 15.-Plethodon gordoni sp. nov. Holotype, USNM 166687.
Fig. 16.-Range map of Plethodon elongatus and Plethodon stormi.
Fig. 18.-Key characters in the western Plethodon. Symbols: A,E,G,H, dunni; B, elongatus; C, larselli; D, vandykei; F,I, vehiculum.
Western salamanders of the genus Plethodon constitute three species groups: Vandykei group (vandykei, larselli), Vehiculum group (vehiculum, dunni, gordoni sp. nov.), and Elongatus group (elongatus, stormi). P. gordoni is described as closely related to dunni, and subspecies of vandykei are not recognized due to the discordant nature of geographic variation. Each species is described in detail and a key to the species is provided. A dendrogram of proposed evolutionary relationships is presented; P. vandykei is considered the most primitive and elongatus is considered the most specialized. Character displacement is exhibited by sympatric dunni and gordoni. Character convergence occurs for dunni where it is sympatric with larselli and elongatus. Geographic variation in costal groove number, tooth numbers, limb length, pigment characters, and head shape was examined in each species. The number of maxillary plus premaxillary teeth was shown to be valuable in determining phylogenetic relationships. Significant geographic variation is present in vandykei, larselli, vehiculum, dunni, and elongatus but subspecific designations are not justified.