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Records of the Australian Museum (2009) Vol. 61 
Figure 26. A-K, Hydroides trihamulatus n.sp., specimen from AM W202944: (A,B) anterior parts of tube; (C) part 
of tube with worm in situ; (D) worm removed from its tube; (E, F) enlarged view of operculum, note swollen tips 
of unmodified coronal spine and infundibular spines; ( G-J) bayonet-shaped special collar chaetae; (K) anterior 
abdominal uncini; (L) thoracic uncini. 
Genus Serpula Linnaeus, 1758 
Type species. Serpula vermicularis Linnaeus, 1767 
Diagnosis. Operculum chitinous; funnel-shaped, bearing 
dichotomous radii ending in marginal lobes; inserted in 
position of second branchial radiole; peduncle non-pinnulate; 
inter-radiolar membranes absent. Number of thoracic 
chaetigers: seven. Apron: present. Special collar usually 
bayonet shaped, bearing two to a number of teeth on boss. 
Most anterior uncinal tooth: larger than the rest. Distal ends 
of abdominal neurochaetae shaped like asymmetrically 
“flattened trumpets”, with one side longer than other, and 
bear numerous serrations or denticulations. Tube: devoid of 
internal tube structures. 
Remarks. The shape and range in number of the radial 
lobes in adult opercula, besides other characters, are useful 
in distinguishing species belonging to the genus. 
Serpula amplilobata n.sp. 
Figs 27A-K, 28A-E 
Material examined. Kimberleys, Western Australia, holotype: AM 
W21410, east Montalivet Island 15°06'S 125°18'E, 6 m, 15 Jul. 1988, st 
50; coll. P.A. Hutchings. 
