Pillai: Serpulid polychaetes from the Australian Kimberleys 
111 
Figure 56. A-I, Spirobranchus pseudopolytremus n.sp., from Cronulla, NSW Australia: BMNH 1959.10.19.39 (2 specimens) collected 
and presented by Barbara Dew. ( A,B ) two views of tube; ( C ) dorsal view of holotype; (D) ventral view of anterior end of latter; (E) left 
lateral view of operculum of latter; ( F,G ) two views of operculum of paratype; ( H) branchial radioles showing the pinnule-free tips and 
unfringed inter-radiolar membranes; (7) two special collar chaetae with two slender capillaries accompanying them. 
Worm. Operculum on left side, no rudimentary operculum 
on right. Number of radioles: 15 on the left and 14 on right 
in holotype; 18 on each side in paratype. Operculum conical, 
its peak dorsally curved (Fig. 56C-G); although the peak 
is dorsally directed in holotype, it is a short cylindrical 
stump in paratype (Fig. 56C-E). A fine granular overlay 
can be seen at higher magnifications under certain angles 
of illumination (Fig. 56G). Opercular peduncle fringed 
(Fig. 56G). Dorsolateral and ventral views of the holotype 
presented in Fig. 56C,D. Radioles arranged in a circle; 
their pinnule-free tips thicker than and somewhat longer 
than preceding pinnules. Inter-radiolar membranes present; 
unfringed (Fig. 56H). Collar conspicuously broad (Fig. 
56C,D); thorax consists of 7 chaetigers; prostomial ocelli and 
thoracic glands not discernible; apron, present (Fig. 56D). 
Abdomen of holotype has about 45 segments. Abdominal 
tori, short and lateral (Fig. 56D). 
Chaetae. Special collar chaetae stout and truncated, like 
acicula, serrated (Fig. 561); no indication of a boss or serrated 
