T.G. PILLAI AND HA. TEN HOVE 



peristome at its anterior end (Fig. 24, A). The ventral side of 

 the unattached part, which commences from a swollen attach- 

 ment to the substratum, does not show the granular overlay 

 but only faint transverse wrinkles (Fig. 24, B). The peristome 

 consists of a broad triangular dorsal lobe which is continuous 

 with two narrow ventro-lateral lobes (Fig. 24, A,B).The 

 inside of the tube is quite shiny. It attains a diameter of 

 1.6 mm at the peristome, and 1.5 mm at the swollen com- 

 mencement of the unattached part. 



ITS, which are present only in the posterior part of the tube, 

 consist of an unserrated dorsal ridge (Figs. 24, C; 25, B,C), and a 

 very short smooth ventral ridge (Fig. 3, 1), which is very short in 

 the holotype (Fig. 25, D); in the specimen from Lizard Island the 

 ventral ridge is smooth to scalloped. The dorsal ridge may be 

 T-shaped in cross-section in places (Fig. 25, C) but appears 

 irregular if damaged (Fig. 24, C, middle). In the middle region of 

 the tube, tear-shaped depressions are present in the inner wall, 

 up to 0.2 mm in size. 



worms: The holotype from Taka Bone Rate, broken in three 

 parts (Fig. 25, E-G), has a total length of 31.5 mm, a thoracic 

 width of 0.5 mm, an abdominal length of 27.0 mm and 117 

 segments, with capillaries on the last 8. Its radioles are 

 2.7-3.0 mm long, of which the slender pinnule-free tips consti- 

 tute 0.3 mm. Paratype I lacks its branchial crown; it has a length 

 of 5.0 mm, a thoracic width of 0.4 mm, an abdominal length of 

 4.3 mm, and has 61 segments, with capillaries on the last 15 orl6. 

 Paratype II, from Tukang Besi Island, lacks its radioles on the 

 right side, and its abdomen is in several parts. Its thorax, 

 however, is intact (Fig. 24, G,H). 



The operculum and peduncle measure 3.0 mm long in the 

 holotype, 4.1 mm in paratype II. Other measurements and 

 counts are given Table 19. 



The operculum is zygomorphic, and its distal end is quite 

 different from that of other known species of the genus in being 

 markedly convex (Figs. 24, D-F; 25, G-J). The cuticle is thick- 

 ened and transparent, particularly in its convex distal end, the 

 marginal lobes of the radii, and the asymmetrical projection at 

 the base of the operculum. The number of radial lobes reaches 

 about a dozen. There is a sharp constriction between the 

 operculum and the peduncle, the latter being slender, except for 

 a slight expansion before the constriction (Figs. 24, E,F; 25, J). A 

 filamentous rudimentary operculum is present on the side 

 opposite to that of the operculum (Fig. 25, G). 



The number of radioles per side reaches 14. Their short 

 pinnule-free tips are about 1/7-1/8 the entire length of the 

 radiole. Prostomial eyes were not found. Thoracic glands are 

 present, transparent in the holotype and paratype II, light 

 brown in paratype I. The number of thoracic segments per 

 side is 7-8, and the thoracic membranes do not reach the last 

 thoracic segment (Fig. 24, G-I). 



The abdomen of the holotype appears glandular ventrally, 

 packed with eggs, and bears peculiar swellings (Fig. 25, E) which 

 fit into corresponding depressions in the tube. It was not possible 

 to find them in the damaged abdomen of paratype II, although 

 this is a mature specimen too, and the inner tube wall shows 

 tear-shaped depressions (0.32 x 0.22 mm); they are absent in 



Table 19 S. iugoconvexa sp. nov. Measurements and other data on 

 type specimens. 



Holotype Paratype I Paratype II 



Length of operculum (mm) 



0.7 



? 



1.0 



Diameter of operculum (mm) 



0.5 



7 



0.7 



No. of radii 



12 



? 



11 



No. of radioles(L/R) 



10 



7/7 



14/? 



No. of thoracic chaetal tufts 



8/7 



111 



in 



Thoracic membrane ends 



111 



1/3 



5/4 



the juvenile paratype I. Possibly, these abdominal swellings are 

 developed in older worms only. 



Collar fascicles of the holotype bear 4 bayonet chaetae 

 each (Fig. 25, K-N). Each possesses a long serrated blade, a 

 short unserrated notch and two teeth on the basal boss, one 

 of which may be difficult to observe in side view since it lies 

 directly behind the other. The number of teeth is clearly seen 

 in one of the bayonets of paratype I which has its blade 

 broken off at its base (Fig. 24, J), although it is difficult to 

 observe in a newly formed chaeta from within the same 

 fascicle (Fig. 24, K). Thoracic uncini bear 5 or 6 teeth (Fig. 25, 

 O), and anterior abdominal uncini 4 or 5 teeth in a single row 

 (Fig. 25, P). There are up to about a dozen flat trumpet 

 chaetae in each bundle (Fig. 25, Q). Their distal ends bear a 

 claw-shaped process on one side and are drawn out into an 

 acute angle on the other. 



Etymology. Iugum (L) = yoke; convexus (L) = bulbous; 

 refers to the zygomorphic, convex operculum. 



Material from other locality. The material from Liz- 

 ard Island agrees closely with that of the type series with 

 regard to collar chaetae, operculum and tear-shaped depres- 

 sions in the inner tube wall. However, the ventral internal 

 ridge has a scalloped edge, not smooth as in the Indonesian 

 material. 



Habitat and distribution. A reef dweller occurring at 

 depths of about 25 m. Hitherto collected from Indonesia 

 (Flores Sea and Banda Sea) and Australia (Queensland). 



Spiraserpula snellii sp. nov. 



(Figs.26, A-X; 27, A-L; 28, A-V; 3, F) 



Material examined. 



Flores Sea, (Indonesia): 1. Taka Bone Rate (Tiger Island), 

 Snellius II 4.139B, S. of Tarupa Kecil, 06°30'S 121°8'E, edge 

 of reef flat, 30 m, (HOLOTYPE & 4 PARATYPES: RMNH 

 18298; 4 PARATYPES (+ one abdomen & internal tube 

 ridge): BM(NH) 1992.66-71; 5 PARATYPES & tube mate- 

 rial: ZMA V. Pol. 3738; 3 PARATYPES & fragmentary tube 

 material: USNM 130983 & 130984). 





Fig. 23 Spiraserpula sumbensis sp. nov. A-M, Holotype. O-U, Paratype. A-D, O, Tubes showing granular overlay and faint transverse 

 growth ridges; A, An erect part; B, also showing body, operculum & radioles in situ; C & D, two views of same tube fragment showing 

 wedge-shaped dorsal and ventral ridges, both unserrated. E, Operculum. F & G, Holotype. F, Radioles showing zygomorph operculum on 

 left, rudimentary operculum on right. G, Worm showing extent of thoracic membrane. H-K, Bayonet collar chaetae. L, Thoracic uncini. 

 M, Anterior abdominal uncini. N, Bundle of anterior abdominal flat trumpet chaetae. O, Tube of paratype, also showing worm with its two 

 opercula in situ. P, Radioles with two well-developed opercula. Q, Two views of thorax showing extent of thoracic membranes. R-U, 

 Bayonet collar chaetae. 





