Plaramia arcata Shear & Marek, 2022

Shear, William A. & Marek, Paul E., 2022, The millipede family Striariidae Bollman, 1893. VI. Six new genera and thirteen new species from western North America (Diplopoda, Chordeumatida, Striarioidea), Zootaxa 5205 (6), pp. 501-531 : 520

Plaramia arcata Shear & Marek , n. sp.

Figs 37–40 , 76–78

Types: Male holotype, 2 male paratypes and female paratype from the north side of Jolly Giant Canyon , Arcata Community Forest, 40.8759°N, - 124.0681°W, 400–600’ asl, collected 21 February 1978 by A. K. Johnson ; two male paratypes from Arcata Community Forest , 40.8699°N, - 124.0725°W, collected 31 March 2011 by C. Richart et al .; two male paratypes (parts of these are on SEM stub WS35-3) from along Jacoby Road and Kilpatrick Quarry Road, 100–200’ asl, T5N, R1E, Sec 14 (40.8279°N, - 124.0390°W) collected 24 November 1977 by A. K. Johnson ; six male and two female paratypes from behind Humboldt State University campus, Arcata Community Forest, 40.8748°N, - 124.0506°W, 200–700’ asl, collected 1 April 1979 by A. K. Johnson. All material deposited in FSCA .

Etymology: The name is derived from the type locality, Arcata Community Forest, and is a noun in apposition.

Diagnosis: The two species of this genus are closely similar, but Plaramia arcata , n. sp., can be distinguished from P. johnsonae , n. sp., by details of the gonopods and ninth legs. The gonopods of the latter species have more curved anterior angiocoxites than the former, with a hooked termination, and the ninth leg telopodites are deeply notched. C6 of this species are very prominent, they are less so in P. johnsonae , but this difference can only really be seen in comparison.

Description: Male holotype. Length 3.8 mm, width 0.4 mm; 30 rings. Two black ommatidia on each side of head ( Fig. 37 ). C6 moderately extended as paranota. Telson lobes shallowly divided, nearly obscure. Metazonital setae obvious only on anterior rings, relatively short, acute. Color after long preservation pale yellowish tan. First legs enlarged ( Fig. 37 , L 1 ), with needle-like setae. Second legpair smaller, when coxae apposite, appearing to have common seminal opening. Flasks of third coxae short ( Fig. 38 , cf), when extended posteriorly reaching to anterior margin of fifth coxae; telopodites with broad, flattened prefemora. Fourth through sixth legs encrassate, podomeres flattened, with prominent characteristic modified setae. Seventh coxae lacking lobes. Gonopods Figs 39, 40 , 76, 77 ) moderately large. Sternum massive, short. Coxae with 3 or 4 setae on lateral side, extended into short, triangular process ( Fig. 76 , cx). Anterior angiocoxites curved laterally, then mesally, without branches, slightly flattened at tip ( Figs 40 , 76, 77 , aac). Posterior angiocoxites small, low, with two processes; reduced to sheath for single flagellocoxite ( Fig. 77 , fc). Single flagellocoxite long, thin, evenly curved, possibly movable (there may be a basal articulation). Ninth legs ( Fig. 78 ) with broad, plate-like coxosternal process ( Fig. 77 , cxp); telopodites ( Fig. 39 , 77 , t 9 ) free, large, flattened, notched on mesal surface to embrace gonopod anterior angiocoxites, laterally fitting tightly into notch in seventh pleurotergite ( Fig. 39 ). Tenth coxae not much swollen, gland openings anteriodorsal.

Females similar to males in nonsexual characters.

Distribution: Known only from Arcata Community Forest, Humboldt Co. California.

Figures

FIGURE 1. Nototrisaria ornata, n. gen., n. sp., live female in habitat. About 5.0 mm long. Photo by Bill Leonard.

FIGURES 35–40. Striariid millipedes. Figs 35, 36. Rampalia cheathamensis, n. gen., n. sp. 35. Coxae of male legpair 7, ventral view. 36. Gonopods, anterioventral view. Figs 37–40. Plaramia arcata, n. gen., n. sp. 37. Head, collum and ring 2 of male, lateral view. 38. Legpair 3 coxae of male, ventral view. 39. Gonopods, ventral view. 40. Right gonopod, mesal view. Abbreviations: aac, anterior angiocoxite; cc, colpocoxite; cf, coxal flask of leg 3; col, collum; cp, coxal process; cx, gonopod coxa; cxs, coxosternite of leg 9; cx5, coxa of leg 5; cx7, coxa of leg 7; L1, leg 1; m, mandible; s, sternum of gonopods; t9, telopodite of leg 9; 2, ring 2.

FIGURES 71–78. Striariid millipedes. 71. Right leg 9 of male Lamparia millicoma, n. gen., n.sp., anterior view. Figs 72– 75. Rampalia cheathamensis, n. gen. n. sp. 72. Right gonopod, lateral view. 73. Right gonopod, mesal view. 74. Male ninth legpair, anterior view. 75. Male ninth legpair, posterior view. Figs 76–78. Plaramia arcata, n. gen., n. sp. 76. Right gonopod, lateral view. 77. Right gonopod, mesal view. 78. Left leg 9 of male, anterior view. Abbreviations: aac, anterior angiocoxite; cc, colpocoxite; cxp, coxal process; cx, gonopod coxa; fc, flagellocoxite; pac, posterior angiocoxite; t9, telopodite of ninth leg.

FIGURES 7–9. Maraplia napa, n. gen., n. sp. 7. Female, lateral view. 8. Head and first legpair of male, ventral view. 9. Coxal flask of leg 3 of male, lateral view. Abbreviation: cf, coxal flask of leg 3.