Pillai: Serpulid polychaetes from the Australian Kimberleys 
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Figure 28. A-E, Serpula amplilobata n.sp., from holotype AM W21410: (A, B) bayonet-shaped collar chaetae; (C) arrangement of anterior 
abdominal uncinal tori; (D) thoracic uncini; (E) anterior abdominal uncini; F-H, Serpula jukesii Baird, 1865, from AM W21934: (F) tube; 
(G) lateral view of operculum; ( H) arrangement of abdominal uncinal tori. 
MLR and a LLR along either side of it clearly recognizable 
in posterior part of tube (Fig. 29G). 
Worm. Distal part of operculum circular, followed by a 
funnel-shaped part, latter like an inverted cone decreasing 
in diameter noticeably and having a constriction between 
latter and a bulbous proximal part before it joins the peduncle 
(Fig. 29H,I). A sharp constriction present between bulbous 
part of operculum and the moderately thick peduncle (Fig. 
29H,I). Opercular radii terminate in 42 rounded marginal 
lobes; their cuticle thin and translucent; tubercles absent (Fig. 
291). Number of branchial radioles: 24 on each side, pinnule- 
free tips moderately long and slender; operculum on right, 
rudimentary operculum on left (Fig. 29H). Thoracic glands 
represented by a pair of openings on ventral side of thorax 
(Fig. 29K), with reddish pigmentation around them. Apron 
is present (Fig. 29K). 
Chaetae. Eight bayonet-shaped special collar chaetae present 
in one of the fascicles examined. Each has a comparatively 
stout shaft, a conspicuously squarish boss which bears 2-6 
triangular teeth, and a transverse row of small serrations, of 
variable length, either preceding them or at the angle between 
the boss and the blade (Figs 29L, 30A-E). An unserrated 
notch is absent (Figs 29L, 30A-E), even in older worn-out 
chaetae (Fig. 30B), a characteristic feature of present species. 
