Benedictesmus aureus 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 : 113-116

Benedictesmus aureus Shear & Marek , n. sp.

Figs 96–101 , 133

Types. Male holotype and male and female paratypes from 13 mi East of Gold Beach on the road to Agness , 42.4932°, -124.2194°, Curry Co., Oregon, collected 10 March 1972 by E. M. Benedict. All types deposited in CAS .

Diagnosis. Distinct from B. ellenae , n. sp., which also has 18 rings in males, in the much shorter terminal zone of the gonopod and in having 20, rather than 18 setae in the anterior marginal row on the collum. The other two species of Benedictesmus have 19 rings in males. Females of all known species of Benedictesmus have 19 rings.

Etymology. The species name, an adjective, refers to Gold Beach, Oregon, the type locality.

Description. Male holotype. Eighteen rings ( Fig. 96 ). Length about 3.0 mm, greatest width 0.41 mm. Head densely setose, cuticle alveolate ( Fig. 98 ). Collum with anterior marginal row of 20 setae ( Fig. 98 ).Anterior metazonites with three rows of setae, transitioning to four rows about ring 5, setal tubercles becoming almost obsolete on midbody ( Fig. 99 ) to posterior rings. Alveolate cuticle absent from metazonites posterior to collum. Epiproct ( Fig. 100 ) slightly swollen, short, slightly decurved, with alveolate cuticle. Anterior legs crassate ( Fig. 97 ), tarsi with sphaerotrichomes. Gonopod ( Fig. 101 , 133 ) with moderately inflated prefemorite, distal part of prefemorite with pore field, 3 or 4 setae (ppf, Fig.101 ). Acropodite short, robust, basally flattened. Pulvillus a short tube (p, Fig. 101 ). Distal, pulvillar process (pp, Fig. 101 ) extending over pulvillus as short hood. Terminal zone (tz, Fig. 101 ) short, bifurcate. Females with 19 rings, similar to males in nonsexual characters.

Distribution. Known from the type locality and one site a mile away (14 mi east of Gold Beach), where males and females were collected by E. M. Benedict on the same day as the types.

Notes. The pore field at the distal part of the gonopod prefemorite seems to be unique in this group of small polydesmids; among the pores are three or four long, curled setae.

Figures

FIGURES 96–100. Benedictesmus aureus, n. gen., n. sp. 96. Male, dorsal view. 97. Anterior part of male, ventral view. 98. Head and anterior rings, dorsal view. 99. Midbody ring, dorsal view. 100. Pygidium, lateral view. SEM stub WS33-6.

FIGURES 101–106. Species of Benedictesmus, n. gen. 101, Gonopods of Benedictesmus aureus, n. sp., ventral view. SEM stub WS33-6. 102–106. Benedictesmus ellenae, n. sp. 102. Head and anterior rings, dorsal view. 103. Midbody ring, dorsal view. 104. Pygidium, lateral view. 105. Gonopods in situ, lateroventral view. 106. Pulvillus of gonopod. SEM stub WS33- 13.Abbreviations: p, pulvillus; pp, pulvillar process; ppf, prefemorite pore field; tz, terminal zone.

FIGURES 133–137. Drawings of gonopods of polydesmid species. 133. Right gonopod of Benedictesmus aureus, n. sp., mesal view. 134. Right gonopod of Benedictesmus ellenae,n. sp., lateral view. 135, Right gonopod of Benedictesmus yaquina, n. sp., lateral view. Fig. 136, 137, Benedictesmus timber.n. sp. 136, Right gonopod, lateral view. 137, Tip of right gonopod, mesal view. Abbreviation: p, pulvillus.