Rowlandesmus millicoma Shear & Marek, 2021

Shear, William A. & Marek, Paul E., 2021, Three new genera and eighteen new species of miniature polydesmid millipedes from the northwestern United States (Diplopoda, Polydesmida, Polydesmidae), Zootaxa 4975 (1), pp. 81-126 : 111

Rowlandesmus millicoma Shear & Marek , n. sp.

Figs 85–90 , 131

Types. Male holotype and male and female paratypes from 14 mi. E, 2 mi. S of Allegany, Weyerhauser Millicoma Tree Farm , company Road 6000, riparian zone of Fall Creek , 43.3983°, -123.7770°, Coos Co., Oregon, collected 23 November 1971 by E. M. Benedict. All types deposited in CAS .

Diagnosis. Distinct from R. dentogonopus in lacking prominent teeth in the terminal zone of the gonopod and in the more basal position and larger extent of the pulvillus (p, Fig. 90 ).

Etymology. The species name is a noun in apposition and refers to the type locality, the Millicoma Tree Farm.

Description. Male holotype. Length about 3.5 mm, greatest width 0.45 mm. Head densely setose, cuticle alveolate ( Fig. 85 ). Collum with anterior marginal row of 20 setae ( Fig 85 ). Anterior metazonites with three rows of setae, transitioning to four rows about ring 5, setal tubercles low on anterior segments, becoming almost obsolete on midbody ( Fig. 86 ) to posterior rings; some rings with interpolated setae nearly forming fifth row. Alveolate cuticle absent from metazonites posterior to collum. Epiproct ( Fig. 87 ) swollen, short, decurved, lacking alveolate cuticle. Anterior legs crassate, tarsi with sphaerotrichomes. Femur of third leg slightly enlarged. Gonopod ( Figs 88–90 , 131 ) with moderately inflated prefemorite. Acropodite short, robust. Pulvillus (p, Figs 88, 90 ) basal, enlarged, pulvillar process absent. Terminal zone bifurcate, longer distal process (z, Fig. 88 ) narrow at base, then broadened, bent posteriorly at slightly less than right angle, crossing lateral to shorter basal process (x, Fig. 88 ). Females similar to males in nonsexual characters.

Distribution. Coos Co., Oregon.

Records: OREGON: Coos Co.: 11 mi east, 4 mi south of Allegany, Weyerhauser Millicoma Tree Farm, company road 6040, 43.3429°, -123.8435°, 21 November 1971, E. M. Benedict, mm; 6 mi east, 2 mi south of Allegany, Weyerhauser Millicoma Tree Farm, company road 5000, 43.3944°, -123.9111°, 20 November 1971, E. M. Benedict, m, f; 6 mi east of Allegany, Game Commission cabin, 43.4311°, -123.9094°, 20 November 1971, E. M. Benedict, mm.

Figures

FIGURES 85–90. Rowlandesmus millicoma, n. gen., n. sp. 85. Head and anterior rings, dorsal view. 86. Midbody ring, dorsal view. 87. Pygidium, lateral view. 88. Gonopods in situ, lateral view. 89. Same, ventral view. 90. Same, ventrolateral view. SEM stub 33-5. Abbreviations: k, “kink” in gonopod; p, pulvillus; x, y, z, processes of terminal zone.

FIGURES 127–132. Drawings of gonopods of polydesmid species. 127. Tip of gonopod of Retrorsioides castellum, n. sp., mesal view. 128. Right gonopod of Retrorsioides linnensis, n. sp., lateral view. 129. Left gonopod of Retrorsioides kittitas, n. sp., lateral view. 130. Right gonopod of Retrorsioides bannerti, n. sp., lateral view. 131. Right gonopod of Rowlandesmus millicoma, n. sp., mesal view. 132. Right gonopod of Rowlandesmus dentogonopus, n. sp., lateral view. Abbreviations: adp, anteriorly directed process; p, pulvillus; pf, prefemorite; pp, pulvillar process; tz, terminal zone.