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Records of the Australian Museum (2009) Vol. 61 
Figure 9. A-E, Pomatostegus actinoceros. (A) tube of a specimen from AM W21438. B-E, a specimen from AM W202961: (B) anterior 
part of tube; (C) drawing of magnified section of anterior part of tube to show the pitted surface; ( D ) ventral view of thorax; the slit-like 
apertures of the pair of thoracic glands are shown; an apron is absent, although the last of thoracic tori are continuous along the posterior 
edge of the thorax; (E) dorsal view of thorax; the unfringed peduncular wing and the prostomial ocellar cluster on the right side, as well 
as the thoracic membranes of the two sides of the 3rd thoracic chaetiger are shown. 
14°01'S 125°44’E, 20 m, 18 Jul. 1988, st. 60. 1 large specimen, incomplete 
posteriorly from AM W21423, south-west comer of Lucas Island, 15°13’S 
124°31'E, 30 m, 24 Jul. 1988, st 101; 1 specimen, AM 202947, Careening 
Rock, 15°06'S 125°06'E, sand, beach and rocks, intertidal, 13 Jul. 1988, st 
41. 1 small incomplete specimen, AM W23093, Lafontane Island, 14°10'S 
125°47'E, 15 m, 19 Jul. 1988, st 68: all coll. P.A. Hutchings. 
Description 
Measurements. Tube: maximum length of one with its 
posterior part missing: 85.0 mm; maximum external diameter 
of its posterior end, 8.2 mm. Worm: total length of longest 
available complete worm 48.0 mm; its maximum thoracic 
width 5.0 mm. Maximum abdominal length: 30.0 mm. 
Number of abdominal segments in relation to length variable: 
102 for a specimen with abdominal length of 15.5 mm; 98 for 
a less contracted specimen with abdominal length 30.0 mm. 
T\ibe. Crea mi sh white to white, broadly semi-circular to 
obtusely triangular in cross-section; abruptly decreases in 
diameter posteriorly (Fig. 9A). Under higher magnification 
tube surface characteristically pitted (Fig. 9C). About 5 or 6 
lateral longitudinal ridges may be present along each flank; a 
wide flange may be developed in places (Fig. 9A,B). A median 
longitudinal ridge may be more or less clearly developed; 
clearly seen in the posterior third of tube (Fig. 9A); fine 
transverse grooves may extend laterally from it (Fig. 9A). 
Worm. Operculum on left or right side; peduncle fleshy and 
winged (Fig. 9E), bears a chitinous tiered distal part (Fig. 
10A). Latter consists of a central column bearing circlets 
of dark outwardly directed spines at intervals, above each 
of which is a thin, shallow, translucent, yellowish-brown, 
saucer-shaped structure with a scalloped margin; marginal 
scallops not regularly shaped, but more or less rounded, 
flattened and their tips directed posterolaterally. Grooves 
extend between and along scallops to, or part of the way 
towards central column. Saucer-shaped structures may 
completely or partly damaged or lost in earlier formed distal 
tiers. Maximum number of tiers observed in collection 6. 
Maximum number of radioles observed per side, 58. Pair 
of slit-like apertures representing a pair of ventral thoracic 
glands present, (Fig. 9D). Pair of greyish/blackish pigment 
patches, apparently clusters of ocelli, discernible anterior 
to second pair of thoracic chaetal fascicles (Fig. 9E). Seven 
pairs of thoracic chaetal fascicles; thoracic membranes 
extend to of third pair of thoracic chaetal fascicles (Fig. 9E). 
