HEPTABRACHIA BERINGENSIS 



347 



4. Heptabrachia beringensis Ivanov (Figs. 142-4) 



Ivanov, 1960c: 5, 9, 14, 20, 24, 106, 199, 200, 203, 211-5, 265, Figs. 87, 142-4. 



Amongst the abundant pogonophoran material collected in the semi- 

 abyssal zones of the southern part of the Bering Sea were two tubes contain- 

 ing well-preserved animals of a hitherto unknown species of Heptabrachia. 

 The cylindrical fore-part of the body of H. beringensis is six times as long as 

 it is broad, while the short, lappet-like cephalic lobe is flattened dorso- 

 ventrally. The very short protosoma, which is sharply divided from the 

 mesosoma by a straight annular groove, bears a circle of 12-13 free tentacles, 

 each with seemingly triserial pinnules (Figs. 142, 143/4, B). The mesosoma 

 has two secondary, annular grooves in front of the bridle, intersected by a 



Fig. 142. Heptabrachia beringensis: Female. 

 an - girdles; с - cephalic lobe; со - dorsal 

 ciliated band ; / - keel of the bridle ; ms - 

 mesosoma ; pa - papillae of the metameric 

 section ; pa 1 - papillae of the non-metameric 

 section ; pa" - papillae of the zone of thick- 

 ening; pa 3 - metameric rows of papillae; 

 ps - protosoma; sv - ventral sulcus; t - 

 tentacles. 



