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 Retrorsioides linnensis Shear & Marek , n. sp. Figs 59–68 , 128 Types. Male holotype and male and female paratypes from Wells Creek Road , 0.7 mi from SR34, 44.4696°. - 123.4899°, Linn Co. , Oregon , collected 9 December 2005 by W. Leonard and C. Richart. All types deposited in CAS . Diagnosis. The seventh segment of the antenna has a small distal knob set with 6–8 sensilla ( Fig. 60 ). The gonopod ( Figs 66 , 128 ) is short and stout with all processes and the pulvillus clustered near the tip. The prefemorite ( pf, Fig. 66 ) is flattened. The anteriorly directed process has a small basal tooth. Etymology. The species epithet is an adjective referring to the type locality in Linn Co., Oregon . Description. Length about 4 mm , greatest width 0.42 mm . Head densely setose, cuticle alveolate. Collum with anterior marginal row of 18 setae. Anterior metazonites with three rows of setae, transitioning to four rows ( Fig. 62 ) at about ring 5; setal tubercles becoming low on posterior segments. Epiproct ( Fig. 63 ) not swollen, short. Anterior legs ( Fig. 65 ) crassate, tarsi with sphaerotrichomes ( Fig. 64 ). Gonopod ( Figs 66–68 , 128 ) with flattened prefemorite ( pf, Fig. 66 ). Acropodites ( ac, Fig. 66 ) short stout, processes and pulvillus crowded toward tip. Pulvillus ( p, Fig. 68 ) in distal third of acropodite; pulvillar process ( pp, Fig. 68 ) a short, triangular tooth. Anteriorly directed process ( adp, Fig. 68 ) long, flattened, with marginal teeth. Terminal zone ( tz, Fig. 68 ) bifurcate, bent laterally. Female similar in nonsexual characters. Distribution. Linn and Tillamook Cos., Oregon . Records: OREGON : Tillamook Co. : 1 mi west, 0.5 mi south of Lee’s Camp, 700 ft asl, 45.5883°, -123.5349°, 4 November 1972 , E. M. Benedict, mm, ff; FR14, 4.2 mi northeast of SR22, Suislaw National Forest, 900 ft asl, 45.2248°, -123.8337°, 10 December 2005 , W. Leonard, C. Richart, m. f.