Micrograph of Achaeta multisacculata sp. n. A Head lateral view (b = brain, knob on brain marked with black arrow, first dorsal pyriform glands marked with white arrow) B Brain dorsal view (knob on brain marked with arrow) C Cuticle thicker dorsally than ventrally, lateral view D Transverse body wall striation by strong ring muscles E Forepart of body to VII, lateral view (b = brain, ph = pharynx, oe = oesophageal appendages, dorsal pyriform glands marked with black arrows, lateral pyriform glands marked with wider white arrows, ventral pyriform glands marked with narrower white arrows) F Pyriform glands in IV–IX lateral view G Clitellar glands of holotype, lateral view (dorso-laterally 2 elongate, “baguette-like” packages of hyalocytes marked with black arrows, granulocytes ventro-laterally marked with white arrow) H Granular clitellar glands in transverse rows ventrally, lateral view (male openings marked with arrow) I Two baguette-like packages of clitellar glands (marked with arrows, in the middle hyalocytes, on the margins granulocytes) J Segments III–VIII, lateral view (oe = oesophageal appendages with meandering canal, marked with black arrow, dv = origin of dorsal vessel, n = first nephridium, ganglia of ventral nerve cords marked with white arrows) K Segments IV–VIII of paratypes NIBRIV0000813659, No. 2459 lateral view (p = pharyngeal glands, oe = oesophageal glands, spermatheca marked with arrow) A, D–F, H–J in vivo, B–C, G, K fixed, stained. Scale bars: 50 μm, in H, I: 20 μm.