FIGURES 1–4 in The millipede family Striariidae Bollman, 1893. VII. Petra sierwaldae, n. gen., n. sp. a minute millipede from Idaho, USA (Diplopoda, Chordeumatida, Striariidae)

FIGURES 1–4. Male paratype (FMNH) of Petra sierwaldae n. gen., n. sp. 1. Lateral view of anterior end showing head, collum and anterior rings. 2. Collum, lateral view. 3. Rings 2–6, dorsal view. 4. Telson and posterior rings, oblique view. Abbreviations: numerals, ring numbers; cn, notch in collum; hp, hypoproct; L(numeral), leg numbers; om, ommatidium; pp, paraproct; tel, telson.