Ralampia 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 : 523-524

Ralampia Shear & Marek , new genus

Type species: Ralampia complexa Shear & Marek , n. sp.

Etymology: The genus name is an arbitrary combination of letters, an anagram of the related genus name Amplaria forming a Latin neologism to be treated as feminine in gender.

Diagnosis: Three of the striariine genera described in this paper have their metazonital crests all roughly subequal and the sixth crests not especially paranota-like. In Ralampia , n. gen., the gonopods are quite small and compact, the short anterior angiocoxites are reflexed posteriorly and the colpocoxites have long, erect, branched, stiff fimbriae distally. The two species of Plaramia , n. gen., differ from those of Maraplia , n. gen., in that the gonopod anterior angiocoxites are erect and sinuously curved, rather than reflexed anteriorly and either short or if long, curved in an arc.

Description: Small striariines, about 5 mm long. Thirty postcephalic rings, including telson ( Fig. 46 ). Two ommatidia on each side of head ( Fig. 45 , om). Head densely setose, with small tubercles. Labral hook lacking. Mandibular stipes with serrate margin, acute triangular process. Collum with crests limited to posterior region, studded with small tubercles. C6 nearly subequal with C1–5, but oriented horizontally ( Fig. 46 ); metazonital setae short, with brush-like tips. Telson with lobes very shallowly demarcated or nearly indiscernable, sulci shallow. Legpair 1 ( Fig. 47 ) larger than legpairs 2 or 3, femora and tibiae with long, needle-like setae, tarsus with comb. Legpair 2 with short telopodites, vas deferens openings in coxae facing mesally, coxae notched so that when appressed, a single pore is formed. Legpair 3 ( Fig. 48 ) with relatively short flasks, barely reaching fifth coxae when extended posteriorly, heavily set with raised cuticular scales, few contorted setae. Legpairs 4–7 crassate, legpair 7 lacking coxal lobes.

Gonopods small, compact ( Figs 79–82 ). Gonopod sternum large, broader than long. Coxa evidently lacking setae or with 3–4 setae, coxal processes short, quadrate ( Figs 79, 81 , cp). Anterior angiocoxites short, somewhat decurved posteriorly, with lateral flange ( Figs 79–82 , aac). Posterior angiocoxites with several branches ( Fig. 80 , pac), at least one of which appears like flagellocoxite. Flagellocoxites not observed. Colpocoxites oblong, with distal fimbria or crown of branched lamellae ( Figs 80, 82 , cc).

Ninth legs ( Fig. 83 ) with coxosternite and free telopodites. Coxosternite with short, blunt, but complex process. Telopodite large, mesally elongate, with pebbled sculpture and setae, with deep notch to accommodate gonopods. Telopodite locks into deep notch in ventrolateral margin of pleurotergite 7.

Tenth legs with coxal pores, coxae slightly enlarged.

Distribution: Del Norte Co., California, and Curry Co., Oregon.

Note: This genus is the most problematical of those described here. We cannot be certain that the two species are congeneric, but place them here based on the overall similarity of the small, compact gonopods and the body form. If a single gonopod feature uniting them is required, we can point to the elongate colpocoxites with long, apical fimbriae. However, there are differences in gonopod details—for example, Ralampia filamentosa , n. sp., has a gonopod branch divided into many long filaments that is absent in R. complexa , n. sp., while the latter has numerous complicated branches that seem to arise from the posterior angiocoxite region. In neither species could the presence of a flagellocoxite be confirmed, though both have what appear to be posterior angiocoxite branches that look like flagellocoxites. But these are not sheathed. The probable absence of flagellocoxites would argue for placement in Trisariinae , but because we cannot be sure of that, and because the ninth leg telopodites are free, we retain them in Striariinae . Fresh material suitable for more detailed study is required to resolve the difficulties in Ralampia , n. gen.

Figures

FIGURES 45–48. Striariid millipedes. Fig. 45. Ommatidia and Tömösváry organ of Ralampia complexa, n. gen., n. sp. Figs 46–48. Ralampia filamentosa, n. gen., n. sp. 46. Female, lateral view. 47. Right leg 1 of male, posterior view. 48. Legpairs 2–5 of male, ventral view. Abbreviations: L2–5, legs 2–5, respectively; om, ommatidium; To, Tömösváry organ.

FIGURES 79–83. Striariid millipedes. Figs 79, 80. Rampalia complexa, n. gen., n. sp. 79, Right gonopod, lateral view. 80. Right gonopod, mesal view. Figs 81–83. Rampalia filamentosa, n. gen., n. sp. 81. Right gonopod, lateral view. 82. Right gonopod, mesal view. 83. Left leg 9 of male, anterior view. Abbreviations: aac, anterior angiocoxite; cc, colpocoxite; cp, coxal process; cx, gonopod coxa; cxs, coxosternum of ninth legs; fc, flagellocoxite; pac, posterior angiocoxite; s9, sternum of ninth legs; t9, telopodite of ninth leg.