92 



T.G. PILLAI AND HA. TEN HOVE 



total length of the worm ranges from 4.5-6.5 mm. There are 

 4-6 pairs of branchiae with pinnule-free tips. A hollow 

 operculum with about 22 lobes is present on one side, with a 

 pseudoperculum on the other. The collar has a pair of lateral 

 elongations on the median lobe. The thorax has 9 or 10 

 segments on each side, and the bayonet collar chaetae have 2 

 conical processes at the base of the blade. 



The holotype (AM W4018) is in very poor condition. When 

 it was examined by the second author in 1979, the poorly 

 preserved worm, still within its tube, lacked both an opercu- 

 lum and a rudimentary operculum, although there appeared 

 to have been one on one side and none on the other. Other 

 observations were as follows: A cluster of pigmented ocelli 

 present at the base of each branchial lobe; bayonet collar 

 chaetae possess 2 conical teeth, with 1-3 accessory conical 

 teeth; the anterior abdominal uncini of two types: some with 

 a single row of teeth, others in which the posterior tooth is 

 split into two; middle abdominal uncini appeared to possess 7 

 simple teeth in side view; in edge view, however, four 

 anterior teeth are single and the rest are rows of 3 minute 

 teeth each. 



However, examination of topotypical material collected on 

 the same date as the holotype and determined by Straughan 

 (AM 4019, ZMA V.Pol. 3450) yielded the following addi- 

 tional data: The tube has a pair of light pink longitudinal 

 bands (Fig. 29, A), not clearly defined dark pink stripes as 

 mentioned and figured in the original description. It is coiled, 

 somewhat flattened against the substratum, but the free 

 surface is rounded. The coils are bonded together. A granular 

 overlay is present, but it is extremely fine and can only be 

 seen in places, under special illumination (Fig. 29, F). A short 

 erect portion is present (Fig. 29, A,B), with a four-lobed 

 peristome similar to that of S. massiliensis. 



The most important data obtained during the present study 

 of this topotypical material is that S. lineatuba has ITS. They 

 consist of an unserrated dorsal ridge along the convex wall 

 (Fig. 29, B,C,E,F), and a serrated ventral ridge along the 

 opposite wall (Figs. 29, D,F; 3,L). The former may be high in 

 the first formed coil (Fig. 29, E, F, bottom left), or low 

 anteriorly (Fig. 29, B,C), and is wedge-, tongue- to somewhat 

 T-shaped in cross-section. 



The worm is 6.5 mm long, its thorax is 0.5 mm wide, and 

 its abdomen is 4.5 mm long. There are 5 radioles and a 

 slender rudimentary operculum on one side. The median lobe 

 of the collar has only one forwardly directed process, in 

 contrast with the original description, indicating that this is a 

 variable feature. There are 7 pairs of thoracic chaetal tufts, 

 and the abdomen has 49 segments, with capillaries on the last 

 19. Two clusters of prostomial ocelli are present and the 

 thoracic membranes do not extend to the last thoracic chaeti- 

 gers, but end on the fourth and fifth. 



There are 5 bayonet chaetae in each collar fascicle, each 

 with a moderately long serrated blade, a moderately long 

 unserrated notch which is 1/3-1/4 the length of the blade, and 

 2 or 3 conical teeth on the basal boss (Fig. 29, G-J; PI. 3, E). 

 In bayonets with two large teeth, a single accessory tooth may 



be present between them (Fig. 29, G,H,J). Thoracic uncini 

 bear 5 or 6 teeth. As seen in edge view, in the outermost 

 uncini of the row, 3 to 5 of the anterior teeth are single, while 

 the remaining teeth are subdivided into 2 or more smaller 

 teeth which form a short, rasp-shaped posterior cluster 

 (Fig. 29, L). Anterior abdominal uncini are similar (Fig. 29, 

 N). However, SEM of anterior abdominal uncini of another 

 specimen showed a single row of teeth in edge view (PI. 3, F). 

 It appears, therefore, that both types of uncini may some- 

 times be present. Posterior abdominal uncini are rasp- 

 shaped, except for the single anterior tooth. The uncini of the 

 intermediate region show a transition between the two types. 

 Flat trumpet chaetae number about 5-7 per fascicle (Fig. 29, 

 N;P1.3,G). 



A more complete account of the species, however, was 

 obtained from numerous well-preserved specimens collected 

 in 1986 from Split Solitary Island. 



tubes: Have the colouration described above, including the 

 pair of light to somewhat darker pink lateral longitudinal 

 bands. They occur in aggregations of a few to numerous 

 individuals, highly coiled amongst themselves and mutually 

 bonded together, particularly at their bases (Fig. 29, O). 

 Erect parts are sometimes present, and they may bear 

 four-lobed peristomes (Fig. 30, A). The uncoiled part of one 

 of the longest tubes measures 26.7 mm; together with its 

 coiled part it is approximately 30.0 mm long, and its maxi- 

 mum external width is 1.1 mm. 



ITS consist of an unserrated dorsal ridge, a serrated ventral 

 ridge and, usually, a pair of accessory dorso-lateral ridges 

 (Figs.29,0, middle left; 30, B,C; 3, L; Pl.l, A,C,D). The 

 dorsal and ventral ridges of the tube are applied to corre- 

 sponding longitudinal mid-dorsal and mid-ventral abdominal 

 grooves (Figs. 30, D-F). 



Eighteen worms from Split Solitary Island provided impor- 

 tant additional data. Measurements and other meristic data 

 from 8 complete specimens of total lengths ranging between 

 15.9 mm and 1.3 mm presented in Table 21 show that the 

 worms can attain two and a half times the length mentioned 

 in the original description. The maximum number of abdomi- 

 nal segments counted is 89: 



Thirteen complete anterior ends all possess an operculum 

 on one side, a rudimentary operculum on the other, and 5 

 pairs of radioles. The pinnule-free tips are about 1/4 the 

 length of the radioles and are as thick as the pinnules (Fig. 30, 

 D,E). The length of the operculum together with its peduncle 

 ranges between 0.8 mm in the smallest specimen to 1.6 mm 

 in the largest; the length of the operculum itself from 0.3 mm 

 to 0.7 mm, and its diameter from 0.4 mm to 0.6 mm, respec- 

 tively. All the opercula are zygomorph (Fig. 30, D,F), their 

 distal ends are concave and the radii end in somewhat pointed 

 lobes. Many of the latter are actually double, the sub-dividing 

 grooves being only about 1/3 the length of the main interra- 

 dial grooves which extend to about half the opercular length. 

 Thus the total number of about 17-23 radii end in about 

 double the number of marginal lobes (Fig. 30, D-F). The 

 constriction between the peduncle and the operculum is 



Fig. 28 Spiraserpula snellii sp. nov. A-J, from Stn. 21, Lizard Island, Australia. K-Q, From Loyalty Is. R-W, from Egypt. A-B, Tube 

 lacking scutes and granular overlay, but with faint transverse grooves between transverse areas (representing scutes ?). D-E, Same worm 

 with fully formed operculum. E-G, worms showing early vesicular operculum. H, Bayonet chaetae. I, Thoracic uncini. J, Anterior 

 abdominal uncini. K, Anterior fragment of a tube showing branching and a peristome. L, Another fragment showing transverse ridges. M, 

 Juvenile tube. N, Fractured end of a tube showing a thick wall and a T-shaped ventral ridge occupying most of its lumen. O-O, Tube 

 fragments with varying form and thickness of the T-shaped ventral ridge. R & S, Anterior tube fragments, R with peristomes. T-W, tube 

 aggregations with fractured ends showing the T-shaped ventral ridge. W, V, with longitudinal view of ventral ridge. 





