Capa & Murray: Australian Megalomma sabellid polychaetes 
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Figure 7. SEM of Megalomma interrupta n.sp. paratype, AM W35479. (A) anterior thoracic chaetiger and posterior peristomial ring collar, 
ventral view; ( B ) same, dorsal view; (C) thorax and branchial crown junction, showing dorsal collar margins, lateral view; (D) chaetae 
fascicle, first thoracic chaetiger, ventral view; (E) companion chaetae, second thoracic chaetiger; ( F) uncini, same chaetiger; (G) uncini, 
last thoracic chaetiger; (H) last thoracic notochaetal fascicle, ventral view; (7) anterior abdominal neurochaetal fascicle, ventral view; ( J ) 
anterior abdominal uncini; ( K) subdistal compound radiolar eye. 
end on SEM stub, crown in vial), Cullen Bay Marina, Darwin Harbour, 
12°27'09"S 130°49'18"E, coll. CSIRO CRIMP survey team, 30 Mar. 1999; 
MAGNT W17355 (1 detached crown only), same site and collectors; 
MAGNT W17356 (1 spec.). Inner Stokes Hill Wharf, Darwin Harbour, 
S12°28'13"S E130°50'59"E, coll. CSIRO CRIMP survey team, 16 Aug. 
1999. Queensland. AM W35502 (1 crown + spec, on SEM stub), Lorim 
Point Wharf, Weipa,12°40'S 141°57’E, P990 WI, coll. CRC Reef Research 
Centre Ltd, Oct. 1999, from pile scraping, 7 m. 
Description. Only one specimen (MAGNT W331) complete, 
the rest are missing posteriors or in poor condition (branchial 
crown is detached from body). Complete specimen with 
10 thoracic and 120 abdominal chaetigers. Crown with 
18 radioles on each semicircular lobe. External margin of 
radioles rounded, without lateral flanges. Tip of radioles 
digitiform and longer than distal pinnules, except radioles 
bearing compound eyes, where tip is shorter. Radiolar 
skeleton with 8-10 rows of cells (Fig. 5C). Three pairs of 
dorsalmost radioles with subdistal compound eye, with 
distinct ommatidia, diminishing in size ventrally and with 
dorsalmost pair of eyes almost surrounding the radiole, 
leaving a small gap on the outer margin. Dorsal lips with 
radiolar appendages as long as two thoracic chaetigers. 
Ventral lips rounded and well developed. Parallel lamellae 
