16 



PART I. GENERAL ACCOUNT 



■• -3 



ш — ?P 



I 



Fig. 9. Front part of the metasoma of Zenke- 

 vitchiana longissima from the right side. 

 со - dorsal ciliated band ; gp - male genital 

 aperture on the genital papilla; gf-pyriform 

 glands; ms-hind part of the mesosoma; 

 pa - adhesive papillae ; s 2 - groove between the 

 mesosoma and the metsaoma; sph -spermato- 

 phores seen by transparency. (After Ivanov, 

 1957a.) 



Fig. 10. Part of the metasoma of a female Siboglinum caulleryi in the region of the genital openings 



and the zone of thickened papillae. Seen from the ventral and partly from the left side. 



gp - genital opening; о - egg seen by transparency through the body wall, lying in the oviduct; 



pa - papillae of the thickened zone; vv - ventral blood vessel seen by transparency. (After Ivanov, 



1960a.) 



