Three new genera and eighteen new species of miniature polydesmid millipedes from the northwestern United States (Diplopoda, Polydesmida, Polydesmidae) Author Shear, William A. Professor Emeritus, Department of Biology, Hampden-Sydney College, Hampden-Sydney VA 23943; present address 1950 Price Drive, Farmville VA 23901. Author Marek, Paul E. 0000-0002-7048-2514 Associate Professor, Department of Entomology, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061. pmarek @ vt. edu; https: // orcid. org / 0000 - 0002 - 7048 - 2514 pmarek@vt.edu text Zootaxa 2021 2021-05-24 4975 1 81 126 journal article 6194 10.11646/zootaxa.4975.1.3 529d48db-4299-4e2d-9aaf-6c4178c08b18 1175-5326 4804909 DB7C9028-3EDF-454F-88D0-336624AD1DC4 Bidentogon norcal Shear & Marek , new species Figs 17–20 Types. Male holotype and male and female paratypes from Ingot , Shasta Co. California , collected 3 February 1959 by K. W. Gerhardt. The dissected holotype is mounted on SEM stub WS33-10, deposited in CAS . Diagnosis. The short solenomere of the gonopod ( sm, Figs 18, 19 ) is poorly sclerotized and ornamented with fine, hair-like scales; the terminal zone ( tz, Fig. 18 ) is long with an expanded tip, but flattened, not blunt as in B. expansus . There are 18 setae in the anterior marginal row of the collum. Etymology. The species name refers to nor thern Cal ifornia. Description. Male holotype . Length 5.5 mm , maximum width 0.62 mm . Nonsexual characters typical for the genus. Femora of third legpair expanded. Gonopod prefemora typically flattened. Solenomere ( sm, Figs 18, 20 ) narrow, weakly sclerotized, straight, parallel to long axis of acropodite, set with closely spaced fine, hair-like cuticular scales. Terminal zone with flattened, slightly expanded tip ( tz, Fig. 18 ; Fig. 19 ). Females similar in nonsexual characters to males. Distribution. Known only from the type locality.