Parcipromus, n. gen: a Xystodesmid milliped genus from the Sierra Nevada Mountains, California (Polydesmida)

Abstract

The new xystocheirine genus Parcipromus is proposed for Xystocheir cooki Causey and two new species from the Sierra Nevada Range; they occur from Kings River Canyon, Fresno County, to the Greenhorn mountains in southern Tulare County. The genus occurs at the highest elevations of any Nearctic xystodesmid taxon, as its species live in or near Giant Sequoia Groves at 6-7,000'. Characterized in part by a simple, undivided, and curved acropodite, and a prefemoral process on the outer (caudal) side of the prefemur, Parcipromus differs markedly from other tribal components that possess two or more separate acropodal projections and a prefemoral process on the inner (anterior) surface. The species are distinguished primarily by the acropodal configuration, the length of the prefemoral process, and, if present, the size and shape of the latter's lateral spine. Descriptions are presented for the new taxa along with diagnostic illustrations and a key to species.