SIBOGLINUM TAENIAPHORUM 257 



them are twice as long as the rings (Fig. 127Я). In the hind part of the tube 

 the rings become so short as to be quite insignificant, while the interspaces 

 remain the same length as before (Fig. 1277). The transparent filmy front 

 portion of the tube, 1-5 cm long, has limp walls in which it is possible to 

 make out very faint transverse fibres. The only fragment of tube is 15 cm 

 long; the diameter of the front filmy part is 0-25 mm, of the ringed part 

 0-2 mm near the front and a little more than 0-15 mm near the back; in 

 other words, the tube tapers rather more rapidly than usual. 



To all appearances S. robiistum stands rather on its own amongst the species 

 of Siboglinum. In some ways it recalls S. buccelliferum, for both species have 

 a gap between the ventral ends of the keels of the bridle, both have three 

 girdles, arranged in the same way, and they have rather similar toothed 

 platelets. The first two of these characters, however, are not of any great 

 significance, being found also in species of a very different nature. Thus, 

 S. atlanticum and S. taeniaphorum also have a gap between the ventral ends 

 of the keels of the bridle, but they clearly belong to quite a different group of 

 species, while three girdles are also found in species with a bipectinate 

 tentacle (S. ekmani and S. fedotovi) and also in species lacking pinnules (S. 

 hyperboreum and S. tenue). 



Material : a single incomplete specimen in a tube. 



Locality: the northern part of the Coral Sea near Treasury Island 

 (7°30'S 154°15'E) in the British Solomon Islands. 



Depth: 960 m. 



23. Siboglinum taeniaphorum Ivanov (Figs. 128-30) 



Ivanov, 1960c: 5, 12, 14, 18, 28, 96, 98, 105, 128, 188-92, 195, 197, 263, Figs. 87, 

 128-30. 



In August, 1957, during a cruise of R.V. Vityaz\ a few trial dredgings were 

 taken near the north coast of Morotai in the Molucca Islands, at a depth of 

 с 300 m. Amongst the washings from the silty soil was found a transparent 

 white tube, containing an intact female, sharply distinguished from all other 

 species. From the possession of longitudinal glandular ribbons on the 

 mesosoma, so obvious even at first glance, this species has been named 

 S. taeniaphorum [Greek тащ'а, Latin, taenia, a ribbon, Greek фброр, a 

 bearer]. A little flattened dorso-ventrally, the fore-part of the body is un- 

 commonly long, with a length to breadth ratio of 10 : 1. The small protosoma 

 is divided from the mesosoma by a distinct annular groove (Fig. USA, 

 В, C), and in front it runs gradually, without interruption, into the pointed 



