Capa & Murray: Australian Megalomma sabellid polychaetes 
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developed breast, handle about 3.5 times the length of the 
distance from breast to main fang (Fig. 4A). Companion 
chaetae with asymmetrical membrane with most of surface 
covered with fine teeth (Fig. 3B,C). Abdominal neuropodia 
with slender broadly hooded chaetae (Fig. 3F,G). Abdominal 
notopodial uncini with crest of teeth similar to thoracic uncini 
(Fig. 3E) but with handles half the length of thoracic ones 
(Fig. 4B). Pygidium damaged (Fig. 2E). Tough chitinous tube 
present, embedded externally with shell fragments. 
Colour pattern. Body unpigmented, radioles purple, with 
around three-four irregular broad transverse bands; proximal 
band most intense and largest, with more irregular patches 
distally on radioles (Fig. 2A). 
Variation. Complete paratype, 95 mm long, 6 mm wide, 
with eight thoracic and 120 abdominal chaetigers; pygidium 
damaged. Branchial crown with 30 pairs radioles, 24 pairs 
with eyes. Incomplete paratype, with eight thoracic and c. 
10 abdominal chaetigers. Branchial crown with 25 and 27 
radioles in right and left lobes; with subdistal eyes missing 
from ventralmost 5-7 pairs of radioles. Colour pattern similar 
in all three specimens. 
Reproductive features. Incomplete paratype with oocytes 
in the ten anterior abdominal segments (rest of abdominal 
chaetigers missing). 
Etymology. The name of this species is given in dedication 
to Dr Phyllis Knight-Jones in recognition of her great 
contribution to sabellid taxonomy. 
Remarks. This new species shares some characters with 
others described from the Indo-Pacific: M. suspiciens (Ehlers, 
1904) recorded from New Zealand, and M. multioculatum 
Fitzhugh, 2002, from Thailand. These characters are 
the dorsal margins of collar fused to the faecal groove, 
dorsolateral collar pockets present, and subdistal eyes present 
on most branchial radioles. 
Megalomma phyllisae n.sp. and M. suspiciens (Ehlers, 
1904) both possess the same type of inferior thoracic 
chaetae (type B) as well as long-handled thoracic uncini. 
Furthermore, they share the presence of a smooth, rounded 
and dorsoventrally-directed “keel” between the dorsal lips, a 
feature observed after examining the types of M. suspiciens 
and which Tovar-Hernandez & Salazar-Vallejo (2008) 
misinterpreted as a caruncle (p. 1957). Both taxa also lack 
interramal “eyespots” although they were recorded as present 
in M. suspiciens by Tovar-Hernandez & Salazar-Vallejo 
(2008 p. 1957), probably mistakenly, as they subsequently 
state these are absent on p. 1961. Megalomma phyllisae n.sp. 
possesses eyes on most of the radioles but in M. suspiciens 
they are only present in 8-9 of 16-18 pairs of radioles 
(less than half) and the eyes are smaller in the new species. 
Collar margins have more shallow dorsolateral incisions 
and deeper pockets compared with those of M. suspiciens, 
and short dorsal lappets are present in M. phyllisae n.sp. 
and absent in M. suspiciens. The new species differs from 
M. suspiciens in the length of the thoracic uncini handles, 
with approximately 3.5 times the length of the distance from 
main fang to breast in M. phyllisae n.sp., compared with 
about twice the length form breast to fang in M. suspiciens 
(Fig. 4K), and also in the length of abdominal uncini handles 
(Figs 4B,F). Other min or differences include the presence 
of three pinnular appendages per dorsal lip in M. phyllisae 
n.sp. compared with a single pinnular appendage in M. 
suspiciens, the development of the ventral lappets which 
are long and overlapping in M. phyllisae n.sp. and short and 
non-overlapping in M. suspiciens, and the relative position 
of the thoracic ventral shields to the neuropodial tori with 
obvious gaps between tori and shields in M. phyllisae n.sp. 
and which abut in M. suspiciens. 
Megalomma phyllisae n.sp. andM. multioculatum differ 
by the shape of the inferior thoracic notochaetae type B in 
the new species and type A in M. multioculatum ). Other 
differences include the number of rows of cells in the radiole 
structure, with more than 25 in M. phyllisae n.sp. whereas 
there are four rows of cells in M. multioculatum', and the 
development of dorsal lappets, low in M. phyllisae n.sp. and 
absent in M. multioculatum. 
Another species recorded in the Indo-Pacific that shares 
similar features is M. trioculatum Reish, 1968, from Marshall 
Islands, but after reviewing the paratypes (Fig. 2F-I) there is 
no doubt that there is a misinterpretation of morphology in 
the original description of this species. The dorsal margins 
of collar are clearly separated from the faecal groove, ending 
laterally and abruptly, and not producing any pockets on the 
sides (Fig. 2G). Therefore, M. trioculatum should now be 
included with those from Knight-Jones’ Group 2C (Table 
2). Megalomma phyllisae n.sp. also is distinguished from M. 
trioculatum in the shape of the ventral lappets, rounded in 
M. phyllisae n.sp. and pointed in M. trioculatum (Fig. 2F,H), 
and in the length of the thoracic uncini handles (which are 
much shorter in M. trioculatum ). Also, the relative number 
of radiolar eyes is greater in M. trioculatum as all radioles 
of the described holotype and the two paratypes examined 
possess subdistal eyes in all radioles. The number of rows 
in the radiolar skeleton of M. phyllisae n.sp. is higher than 
in M. trioculatum which only bears four (Fig. 5A,G). It also 
has to be mentioned that M. trioculatum does not show three 
types of eyes, as stated in the original description; the two 
paratypes examined possess radiolar eyes only, and these 
are of two sizes, those in dorsalmost radioles are large and 
almost surrounding the whole radiole (Fig. 21), whereas the 
remaining radioles bear small eyes, all similar in size. 
Other Megalomma species resemble the new species in 
the shape of collar dorsal margins and the presence of eyes 
in most radioles. Some of these species can be distinguished 
from M. phyllisae n.sp. by the presence of a caruncle, absent 
in the new species. These are M. lobiferum (Ehlers, 1904) and 
M. carunculata Tovar-Hernandez & Salazar-Vallejo, 2008. 
The new species has short dorsal lappets equal in length to 
lateral collar margins, while other species possess long dorsal 
Figure 2 [continued from facing page]. ... (paratype AM W3548 except L, AM W35479): (7) radiolar crown, ventral view; ( K) detail of 
radiolar eyes; (L) thoracic and anterior abdominal chaetigers, ventral view; (M) posterior peristomial ring collar and anterior thoracic 
chaetigers, dorsal view. (N-Q) Megalomma sp. 1, AM W30022: (N) anterior segments and base of radiolar crown, ventral view; (O), 
same, dorsal view; (P) thoracic and anterior abdominal segments, lateral view; (Q) dorsal most radiolar eyes. 
