60 



T.G. PILLAI AND HA. TEN HOVE 



the Cape Verde Islands. The colouration of the worms in 

 alcohol shows a difference. The radioles and body have an 

 overall fleshy to dark reddish-brown colour, with blackish 

 pigment clusters ventro-laterally in the abdominal segments. 

 Whether this colour difference is due to different methods of 

 fixation or not needs to be verified. Maximum sizes encoun- 

 tered have been given in Table 9. 



An operculum is absent, but a pair of rudimentary opercula 

 is present. Up to 10 thoracic chaetal tufts per side were 

 counted, and the extent of the thoracic membranes is vari- 

 able, however, never reaching the last thoracic chaetiger. 

 Meristic and other data are given in Table 10. 



The collar chaetae (Fig. 6, P-T), are larger than those of 

 the specimens from the type locality, but otherwise similar. In 

 the abdomen, up to 10 flat trumpet shaped chaetae per 

 fascicle were counted. 



The other two Florida samples are similar. However, in 

 sample EJ 67-76, one specimen lacking radioles has 12 

 thoracic chaetigers on the left and 11 on the right, with the 

 thoracic membranes ending on the 6th and 5th chaetiger, 

 respectively. The samples from Bermuda and Aruba are 

 similar to those from Florida. 



Live material. There are some intra-specific colour varia- 

 tions inS. ypsilon sp. nov., as observed in collections from 

 different stations in the Cape Verde Islands: 



Stn.6.D02: Branchial radioles distally orange, proximally 

 pinkish orange, except for a bright red spot where the 

 radioles meet. Thorax is transparently reddish, with two 

 subcutaneous brown spots laterally. Abdomen is pink or 

 orange, with brown sides. 



Stn.7.D03: Distal half of the short radioles banded white 

 and yellowish orange, basal half bright red. Basal radiole 

 parts with oval lens-shaped structures, apparently ocelli. 

 However, after preservation no lenses could be found in this 

 material, not even after staining in methylene blue. Thorax 

 bright red, abdomen orange, with brownish-green granules 

 laterally. 



Stn.7.D05: Radioles transparent, hyaline, with a single row 

 of pigmented spots at the base. No lenses visible, even with a 

 compound microscope. Thorax and abdomen orange-brown. 

 Sides of abdomen show brown granules (in four specimens). 

 In two other specimens the radioles are hyaline, with trans- 

 verse orange bands and red pigment spots at their bases. The 

 rest of the body is red, otherwise similar to the other four 

 specimens. 



Etymology. The specific name refers to the Y-shaped 

 internal ridge. 



Habitat and distribution. As revealed by several scuba 

 dives and littoral surveys in the Cape Verde Islands, 5. 

 ypsilon sp. nov. occurs on various hard substrata in depths 

 occupied by S. massiliensis (Zibrowius) in the Mediterra- 

 nean. At Stn. 6.D02, for instance, the ceiling of a half metre 

 deep cave, at a diving depth of 14m, was covered with crusts 

 of partially erect tubes of 5. ypsilon. However, 5. massiliensis 



did not turn up in any of the collections from the Cape Verde 

 Islands. The single, eroded tube of S. ypsilon sp. nov. from 

 the dredging station 6.148 (100-200 m) was probably trans- 

 ported down the slope. 



Although the Western Atlantic and Cape Verde Islands 

 material show some differences, they appear inadequate to 

 separate them into distinct species. The Western Atlantic 

 range is from Bermuda to Aruba. A species from the 

 Caribbean which has similar internal tube structures, but 

 differs in other respects, is described next. 



Spiraserpula paraypsilon sp. nov. 

 (Figs.8, A-N; 9, A-R; 3, G) 



Material examined. 



Bonaire (Neth. Ant.): 1. Klein Bonaire, N, half mile E of 

 Westpunt, reef, little sand, corals, 38 m, legit H.A. ten Hove, 

 l.vii.1970, Stn. 2105A, HOLOTYPE & PARATYPE 2. 

 ZMA V. Pol.3714; PARATYPE 1, BM(NH) 1992.156. 2. 

 Lac, dam, pool in wash of plunging breakers, Diploria, 

 Millepora, Pontes, cobble in coarse sand, 50 cm, from corals, 

 legit H. A. ten Hove, 15.vii.1970, Stn. 2122C, 

 (PARATYPES 6-8, ZMA V.Pol. 3717). 3. Plaja Frans, on 

 dead coral covered with calcareous algae, little sand, 

 1.0-1.5 m, legit H. A. ten Hove, 16.vii.1970, Stn. 2110A 

 (portions of tube, 1 incomplete worm, BM(NH) 1992.157). 4. 

 Karpata, steep reef, drop off and flat above, 15^ m, from 

 living corals, legit H.A. ten Hove, 19. v. 1987, Stn. 87-5 

 (PARATYPES 4-5, USNM 130992). 



Curacao (Neth. Ant.): 5. Cornelisbaai, sandy reef, from the 

 underside of dead plate-shaped coral, 15 m, legit H. A. ten 

 Hove, 15.xi.1988 (PARATYPE 3 USNM 130991) and 17.i. 

 1990 (4 specimens, AM W20338). 6. Piscaderabaai, outer bay 

 in front of Carmabi, rubbish on reef, 10 m, legit H. A. ten 

 Hove, 10-12.U990 (19 specimens, ZMA V.Pol.3718, 

 BM(NH) 1992.158-165, FSBC I 39196. 7. Salinja Fuik, reef 

 in front, 20-25 m, legit H. A. ten Hove, 18.U990 (25 

 specimens, NSMT). 



Type locality. Klein Bonaire, Curacao. 



Description. 



tubes: White, flattened, and with a granular overlay. The 

 maximum external diameter of the tube of the holotype is 

 2.0 mm. A median and about 3 pairs of lateral longitudinal 

 ridges can be observed (Fig. 8, A). In an empty tube from the 

 type locality with a diameter of 1.5 mm, the number of ridges 

 is less distinct (Fig. 8, B). ITS, located within the first formed 

 coiled parts, are translucent white, and very similar to those 

 5. ypsilon. They consist of a serrated dorsal ridge along the 

 convex wall (Fig. 8, C) and a Y-shaped ventral ridge along the 

 opposite side (Figs.8, D; 3, G). The serrations of the dorsal 

 ridge are pointed and directed somewhat posteriorly. Tubes 

 found on asbestos plates (Piscaderabaai) were clearly branch- 

 ing, as described in detail for S. caribensis (Fig. 16, A & B). 

 worms: The total length of the holotype is 16.4 mm. With a 

 thoracic width of 0.8mm, it is stouter than S. ypsilon. The 



Fig. 9 Spiraserpula paraypsilon sp. nov. A-N, From Klein Bonaire Stn. 2105A; O-R, from Bonaire, Karpata Stn. 87. 5. A-J, From juvenile 

 paratype. A, Tube showing start of external longitudinal ridge and shallow transverse growth markings. B, Posterior tube fragment with 

 serrated dorsal ridge. C, Radioles with long pinnule-free tips, a rudimentary operculum on the left and none on the right. D & E, Two 

 views of body showing pigment patches in both, dorsal an ventral longitudinal abdominal grooves (D), and extent of thoracic membrane 

 (E). F-J, Bayonet chaetae, including one newly formed within the fascicle (J). K-N, From holotype. K & L, Tube fragments (K) and the 

 other from a more posterior coil, with serrated dorsal ridge. M & N, Two views of body showing pigment patches, dorsal and ventral 

 longitudinal abdominal grooves (M), and extent of thoracic membrane (N). O-R, Bayonet chaetae of one specimen. 



