Amplaria arcata, Shear, 2021

Shear, William A., 2021, The millipede family Striariidae Bollman, 1893. II. New records and species of the genus Amplaria Chamberlin, 1941 (Diplopoda, Chordeumatida, Striarioidea), Zootaxa 4908 (2), pp. 205-224 : 212-213

Amplaria arcata , n. sp.

Figs. 15–26

Types: Male holotype and male paratype from Prairie Creek Redwoods State Park , 41.3729833°, 124.0138833°, 252’ asl, Humboldt Co., California, collected 21 December 2006 by C. H. Richart, A. Fusek (Richart collection number CHR 1041). Parts of these specimens are mounted on SEM stubs: WAS33-18, WAS34-1, WAS34-2 and WAS34-3 .

Diagnosis: Distinct from A. rykkenae , the other species in the group, in having the femora of the second pair of legs of the males much enlarged, nearly as wide as long ( Fig. 15 ).

Etymology: The species name is a noun in apposition and refers to the nearby town of Arcata, where the species was also collected

Description: Male paratype. Length about 10.5 mm, width about 1.0 mm. Seven or eight black ommatidia in triangular patch. Labrum with long, sinuate hooks; mandible not modified ( Fig. 15 ). Legpairs 1 and 2 subequal, legs 1 without long setae, tarsi ventrally with twisted, spatulate setae ( Figs. 15–17 ). Trochanters of second legs with short ventral process with patch of specialized setae, femora enlarged, oval, inflated. Coxal flasks of third legs ( Figs. 18 , 21 ) evenly curved, tapering, pleurotergal bars of third ring narrow, not meeting in midline ( Fig. 18 ). Legpairs 4–7 enlarged, with flattened podomeres, coxae unmodified except for lobes on coxae 7. Metazonital crests prominent, more so posteriorly, posterior part of crests raised on rings 21–27 ( Fig. 20 ). Pygidium elongate ( Fig. 19 , 20 ), divisions between lobes deep, narrow. Color medium tan, crests darker, posterior edge of each crest outlined in purplish brown.

Gonopods ( Figs. 25, 26 ) similar to those of A. rykkeni , but with fewer spiculate processes on posteriodistal part of anterior angiocoxites, which bear large, blunt lateral lobes. Ninth legs ( Fig. 24 ) also similar to those of A. rykkeni , articulating loosely with depressions in pleurotergal margins of ring 7.

Female similar to males in nonsexual characters.

Distribution: In addition to type locality known from CALIFORNIA: Humboldt Co.: Arcata, Community Forest east of Humboldt State University, 40.8699°, -124.0725°, collected 31 March 2011 by C. H. Richart et al. mmff.

Figures

FIGS. 14–19. Amplaria rykkenae, A. arcata. Fig. 14. Amplaria rykkenae, posterior end of male, dorsal view. Figs. 15–19. A. arcata. Fig. 15. Left side of head and first two legpairs of male, anterior view. Fig. 16. Tarsus of legpair 1, lateral view. Fig. 17. Special setae of tarsus 1. Fig. 18. Second and third legpair of male, ventral view. Fig. 19. Pygidium, ventral view.

FIGS. 20–24. Amplaria arcata. Fig. 20. Posterior end of male, lateral view. Fig. 21. Legpair 3 of male, anterior view. Fig. 22. Gonopod complex, ventral view. Fig. 23. Special setae of legpair 3.

FIGS. 25–28. Amplaria arcata, A. baughi. Figs. 25, 26. Amplaria arcata. Fig. 25. Right gonopod. posterior view. Fig. 26. Gonopods, posterior view. Figs. 27. 28. A. baughi. Fig. 27. Collum and second ring, dorsal view. Fig. 28. Gonopods, posterior view.