178 
Records of the Australian Museum (2009) Vol. 61 
part of shaft preceding it; at the commencement of serrated 
blade-like part, width of clear unserrated part of shaft is 2Vi 
to 3 times that of serrated part of blade (Fig. 561). Chaetae 
accompanying special collar chaetae highly reduced, in 
comparison. Uncini saw-shaped; thoracic uncini with about 
9 or 10 teeth, and posterior abdominal uncini about 11, 
arranged in a single row, in addition to the anterior gouged 
process; sides of latter pointed and directed outwards. 
Remarks. According to a note in the jar by ten Hove, 
“taxonomic change to be processed = Pomatostegus 
polytrema.” The latter was transferred to the genus 
Spirobranchus by Bianchi (1981: 107). As discussed in 
the remarks under Spirobranchus sp. 1, cf. polytremus 
(Philippi, 1844) earlier in this paper, it appears that there 
are a number of Spirobranchus polytremus -like species in 
the Indo-West Pacific area, which need to be sorted out. 
Imajima (1977: 102-106) remarks that “It is unlikely that” 
the species described by him “will prove to be the same as 
the Mediterranean species”. He decided not to name his 
species in view of the complexity of the group involved, the 
confusion of names by previous authors, and the scarcity 
of data on infraspecific variation of the individual, and 
expressed the need for “a full-scale revision of the group.” 
For the same reason, the S. polytremus-Mke material from 
the Kimberleys was not identified above. 
However, as seen from Fig. 40D-F in this account, and, 
for example, Bianchi (1981: fig. 41c,d) that, although the 
operculum of the Kimberleys and Mediterranean species are 
somewhat similar, there are important differences with regard 
to their tubes. The tube of S. pseudopolytremus n.sp., (Fig. 
56A,B) is quite different from that of S. polytrema from the 
Mediterranean, e.g., as figured by Bianchi (1981: fig. 41a,b); 
while that of the former is wide anteriorly, and abruptly 
narrows posteriorly, it is long and sinuous in the latter. 
The tube of S. pseudopolytremus is superficially similar 
those of two other new species are dealt with in the present 
paper, namely, S. elatensis and S. zibrowii. However, whilst 
the MLR in S. pseudopolytremus is low and ends in an 
inconspicuous process over the aperture (Fig. 56A,B), it 
is high, thick, and ends in a conspicuous projection over 
the aperture in S. elatensis (Fig. 50B) and S. zibrowii (Fig. 
63A,B,D). The three species also differ amongst themselves 
with regard to their opercula. In both S. pseudopolytremus the 
operculum is conical, but whereas that of the former lacks 
any processes at its apex (Fig. 56E-G), that of the latter bears 
a group of reduced S. tetraceros-\\ke processes at its apex 
(Fig. 50C,D). On the other hand, the operculum of S. zibrowii 
bears 2 to a few super-imposed circular discs (Fig. 63E-J). 
Although there are some similarities with regard to special 
collar chaetae among Spirobranchus sp. 3, S. zibrowii and 
S. pseudopolytremus, there are also differences. Those of S. 
sp. 3 lack a boss at the end of the chaetal shaft. However, the 
transition between the end of the shaft and the beginning of 
the blade can be recognized at the bend along the serrated 
side of the chaeta (Fig. 49D). As seen in the latter figure, 
another important character is that the serrated distal part of 
the chaetal shaft is longer than the blade. The special collar 
chaetae of S. zibrowii (Fig. 63K) differ from those of S. sp. 
3 in that the distal part of its chaetal shaft is unserrated, and 
that it lacks a boss. Although the special collar chaetae of S. 
zibrowii and S. pseudopolytremus are superficially similar 
in lacking a serrated distal part of the blade, an elongated 
boss with a faint indentation between the latter and a reduced 
blade can be recognized in those of S. zibrowii (Fig. 63K) 
unlike in S. pseudopolytremus (Fig. 561). Moreover, those of 
S. zibrowii (Fig. 63J) are long and slender compared those of 
S. pseudopolytremus (Fig. 561), which appear to be aciculate. 
Etymology. Named Spirobranchus pseudopolytremus , 
(pseudo = false), to distinguish it from the “5. polytrema 
(Philippi, 1844)-like group of species” which need to be 
sorted out. 
Spirobranchus semperi Morch, 1861 
Fig. 57A-H 
Spirobranchus semperi Morch, 1861: 405. 
Spirobranchus semperi. —Pillai (1960: 17, fig. 6E-I). 
Spirobranchus semperi Morch, 1861, var. acroceros .— 
Willey (1904: 318, pi. VII, fig. 193), Pillai (1960: 18, 
fig. 7A-C). 
Serpula quadricornis. —Grube (1878: 275, pi. XV, fig. 6). 
Material examined. 2 worms and a tube, BMNH 1959.12.16.11/12, Pearl 
Banks, Sri Lanka, collected and identified as Spirobranchus semperi Morch, 
1861 by Pillai (i960?); as S. tetraceros (Schmarda, 1861) by ten Hove 
in 1970, according to a label in the jar. Two worms and a tube, BMNH 
1959.12.16.9, Pearl Banks Sri Lanka, collected and identified by Pillai 
as Spirobranchus semperi Morch, 1861, var. acroceros Willey, 1904; as 
S. tetraceros (Schmarda, 1861) by ten Hove in 1970, according to a label 
in the jar. 
Description 
Measurements. For above specimens identified as S. 
semperi Morch, 1861, by Pillai (1960), as follows: tube at 
aperture, 11.2 mm wide and 5.2 mm high, including the 
median longitudinal ridge; total length of worm 30.5 mm; 
abdomen 18.0 mm. In those identified as and S. semperi 
Morch, var. acroceros Willey, by Pillai (1960): height of 
tube at aperture, 7.0 mm, including median longitudinal 
ridge; total length of larger worm, 17.5 mm, its abdomen 
12.0 mm; 
Tbbe. Colour, in above specimens identified as S. semperi 
Morch, 1861, bright pink in patches on a white background; 
in those identified as S. semperi Morch, var. acroceros Willey, 
pinkish orange at aperture, secondarily overlaid with a light 
bluish-grey colour, apparently by an encrusting organism. 
As regards tube shape, both, those identified as S. semperi 
Morch, 1861, and S. semperi Morch, var. acroceros Willey, 
possess only a single, prominent, thick, sinuous median 
longitudinal ridge, which projects somewhat over the 
aperture (Fig. 57A,B). 
Worm. In both S. semperi Morch, 1861, and S. semperi 
Morch, 1861, var. acroceros Willey, operculum on left 
side, no rudimentary operculum on right. Opercular plate: 
circular; bears 4 stiff chitinous horns, two dorsolateral, and 
two ventral. Each dorsolateral horn bears only a single very 
short dorsomedial branch; short, curved, stiff chitinous spines 
occurring along its branches, simple medially, mostly bifid 
dorsolaterally (Fig. 57C,D). Peduncular wings: fringed. 
Radioles arranged in a circle, 26 on each side in former, 24 
on each side in latter; inter-radiolar membranes present and 
unfringed in both. 
