356 PART II. SYSTEMATIC ACCOUNT 



rest of the preannular region. Most of the paired and unpaired papillae are 

 crowned with transparent oval adhesive plaques, 20/la long (Fig. D1447) with 

 slightly serrated edges. The preannular region is about 17 mm long in both 

 specimens, and the two girdles lie very close together. The toothed platelets 

 are 10 to 20fJL long and are arranged in semi-double rows (Fig. D144//). 

 Their teeth are numerous and small, but difficult to distinguish. The post- 

 annular region, 16 mm of which are present in one specimen, bears some 

 large papillae, which seem to be single, rather than in transverse rows; 

 their adhesive plaques are like those of the preannular papillae. In one 

 specimen some closely packed spermatophores are present. They are about 

 150/x long but their shape cannot be clearly seen. 



"The tubes are up to 10 cm long and their diameter is a little greater at 

 the anterior end than the posterior, being between 0-27 and 0-32 mm. Avery 

 short anterior section of about 1 mm is colourless limp and transparent, 

 while the next 10 mm is yellowish, stiffer and formed of slightly overlapping 

 segments (Fig. D144y4). Towards the end of this part faint brown rings 

 appear and the middle part of the tube has brown rings, yellow interspaces 

 but no overlapping collars (Fig. D144i?). Farther back the rings become 

 paler and finally the whole tube is whitish with faint grey rings (Fig. D144C). 

 Except for the first 1 mm and the last few mm the tube is fairly stiff, though 

 the walls are only about 20/x thick. 



"The overlapping collars and limp anterior end of the tube place this 

 species in the family Polybrachiidae, though the single postannular papillae 

 suggest some affinity with the Oligobrachiidae. Probably the poor condition 

 of the posterior end has made it difficult to see details, and there may be 

 more papillae present. If they really are single then they may represent very 

 reduced 'rows' rather than the condition found in the Oligobrachiidae and 

 Siboglinidae. 



"Heptabrachia {Polybrachia) celebensis is named after the island of Celebes, 

 near which it was collected." 



Heptabrachia celebensis somewhat recalls H. gracilis, in possessing one 

 secondary annular groove on the mesosoma, a small number of tentacles, the 

 same shape and size of cuticular plaques on the metameric papillae. It is, 

 however, distinguished from other species of Heptabrachia by the serrated 

 front edge of the cuticular plaques and by the segmented tube. The rudi- 

 mentary funnels on the latter recall the tubes of Polybrachia. 



Material: two occupied and two empty tubes. 



Locality: Java Sea: Siboga station 212 (5°54'S, 120°19'E). 



Depth: 462 m/| 



