The Sigmocheirini, a xystodesmid milliped tribe in the Sierra Nevada Mountains, California, U.S.A. (Polydesmida: Xystodesmidae)

The xystodesmid milliped tribe Sigmocheirini occupies a band along the western slope of the Sierra Nevada Mountains and eastern fringe of the San Joaquin Valley from Placer to Kern counties, California. It is comprised of two genera, Sigmocheir Chamberlin, with three species occurring from Placer to Tulare counties, and the monotypic Ochthocelata gen. n., the sole component, O. adynata sp. n., occurring in northern Kern County. The species of Sigmocheir display a distinctive, trimaculate pigmentation pattern with yellow middorsal and paranotal spots; the coloration of O. adynata is unknown. Sigmocheir calaveras Chamberlin is a senior name for S. dohenyi Chamberlin, the spelling of which was subsequently corrected to danehyi and assigned to the new genus, Tuolumnia, a synonym of Sigmocheir. Sigmocheir furcata sp. n. is proposed for forms from the northern generic range. The southernmost species is S. maculifer (Chamberlin), comb. n., transferred from Harpaphe Cook. The Sigmocheirini are related to the sympatric tribe Xystocheirini; relationships within Sigmocheir are hypothesized as maculifer + (calaveras + furcata).