Largest specimens up to 84 mm long (holotype is 86 mm long) and 1.7 mm wide at 5th thoracic chaetiger (holotype 5th thoracic chaetiger is 1.7 mm wide); thorax with 7−19 chaetigers (holotype has 19L/17R thoracic chaetigers); thoracic membrane forms well developed ventral apron extending beyond last thoracic segment over the abdomen for equivalent of two segments (Figs 2G−H); abdominal achaetigerous zone maximally as long as thoracic region (Fig. 2H); abdomen up to 335 chaetigers (holotype has 335 abdominal chaetigers). Branchial crown with up to 19 pairs of radioles arranged pectinately (Fig. 2G); crown without operculum, pseudoperculum or modified radioles; radiole tips of different lengths but end at same level (longest radioles are dorsal due to the horseshoe shape of branchial lobe); paired pinnules (up to 100 per radiole) extend to radiole tips; some individuals with short apinnulate tips. Stylodes absent. Without interradiolar membrane, lips or mouth palps. Branchial eyes present (Figs. 2G, 4A). Peristomium with tri-lobed collar: one median ventral and two dorsal flaps, continuous with thoracic membranes, forming apron across anterior abdominal achaetigerous zone. All thoracic chaetae essentially limbate. Apomatus chaetae absent. Collar chaetae plicate at base and grooved tapering to a capillary tip; plicate collar chaetae appear to have "pleats" at the base, with each "pleat" visible (Figs 2B, C). Collar chaetae equal in size to the smallest anterior-most notochaetae of the following thoracic chaetigers. All remaining thoracic chaetae multifolded at base and grooved tapering to capillary tip. Multifolded bases of thoracic chaetae have "folds" which appear to fold into, over and under adjacent folds (Figs 2D−F). Well-developed thoracic tori; torus bears two rows of notochaetae, with up to 53 chaetae per torus and nearly equal numbers of shorter and longer chaetae; notochaetae emerging from anterior side of the torus about half the length of those emerging from posterior side (Fig. 3A); Thoracic uncini first appear in posterior thorax (average = 9th thoracic chaetiger). Thoracic uncini rasp-shaped with approximately 40 teeth in profile, and 1-2 rows of teeth apically to 5-6 rows immediately above and continuing onto elongated (rounded to) rectangular peg, not unlike those figured by ten Hove & Kupriyanova (2009, Fig. 39C) for Protula (dental formula P:5:5:4:4... ...2:2:2:1; Figs 3B, C). Achaetous anterior abdominal zone present. Ventral glandular field extends along posterior-most thorax for up to four segments, and extends up to two segments across achaetigerous zone. Width at 1st abdominal chaetiger up to 2.5 mm (holotype 1st abdominal chaetiger is 1.6 mm wide). Abdominal uncini rasp-shaped with round/rectangular peg and up to 30 transverse rows of seven teeth, decreasing to four teeth per row distally (dental formula P:6:6:6:5... ...4:4:3:2; Fig. 3D). Anterior abdominal neurochaetae flat narrow geniculate (Figs 3E, F). Posterior abdominal neurochaetae are long capillaries (Figs 3G, H), with 1−2 pairs emerging from each segment (average = 16% of posterior of abdomen). Posterior abdominal segments compressed; ventral glandular pad triangular. All specimens of undetermined sex; gametes were never observed in any intact or dissected individuals.
Live specimens white, strongly accented with vermilion-red pigment (Figs 2G, H; 4A). Radioles white, with evenly-spaced red ocelli (simple eyespots) or ocellar clusters (Fig. 4A) (terminology on ocelli follows ten Hove & Kupriyanova 2009). Ocellar cluster length extends over 2−3 pairs of pinnules, occurring at regular intervals (between every six to 10 sets of white pinnules) along radioles for up to 10 clusters per radiole. Most pinnules associated with ocellar clusters pigmented; small individuals with red pigmented radiole tips. Streaks of pigment extend longitudinally from ventral base of crown to ventral collar lobe and transversally to form irregular band on dorsum just posterior to collar lobes. Thorax dorsum strongly red-pigmented from collar to last thoracic chaetiger. Abdominal achaetigerous region lacks pigment. Red pigment patches occur at each chaetal bundle along the entire length of abdomen. All pigmentation lost from worms during fixation in formalin or ethanol; ocelli not visible in preserved material.
Concentrically-coiled worm tubes (Figs 2A, 4B) occur in tight, overlapping aggregations loosely affixed to undersides of smooth rocks; tubes easily removed from substrate with spatula; younger tubes overlie surfaces of older tubes; occupied tubes with straight or curving extension leading to rock edge (Fig. 2A). Individual tubes in less densely-packed aggregates exhibit loose coiling or loosely-curved extensions along rock surface. Tube diameter up to 2 mm, concentrically coiled (diameter to 25 mm); individual coil diameter up to 25 mm (Fig. 2A). Tabulae have not been observed. Tubes opaque and circular in cross-section without internal or external keels or structures (Fig. 4C). External tube surface smooth to fine granular or with transverse growth striations. Internal tube surface smooth and glossy. Younger tubes off-white color, older tubes thicker and with an iron oxyhydroxide stain. Internally, some tubes with a pattern of three perforations through the tube wall, with one hole offset from the other two (Fig. 4D). SEM analysis of tube shows three ultrastructurally different layers: outer layer with irregularly oriented prismatic (IOP) structure; middle layer with spherulitic prismatic structure; inner layer with IOP structure (Figs 4E−H).