DIPLOBRACHIA SOUTHWARDAE 



387 



and the poor development of the metameric region of the trunk. Particularly 

 striking is the absence of adhesive papillae from the anterior part of the 

 metameric region, where instead we see a pair of undivided tracts of pyriform 

 glands. This first stage in the development of secondary metamerism tallies 

 with what we have observed along the whole of the anterior 'metameric' 

 section of the trunk in Oligobrachia dogieli. Finally, Diplobrachia south- 

 wardae possesses somewhat larger cuticular plaques than the other species 

 of the genus, particularly on the papillae of the zone of thickening, and a 

 characteristic spermatophore. 



Material: 11 tubes with animals or fragments of animals and 21 empty 

 tubes. 



Locality: Vityaz 1 station 4620 (31st cruise): Arabian Sea to the west of 

 the coast of southern India. 



Depth: 1300 m.] 



Table 4 

 Characteristics of the species of Diplobrachia 



D. japonic a D. belajevi D. capillaris D. southwardae 



Number of tentacles 

 Length of the fore-part (mm) 

 Breadth of the mesosoma (mm) 



Breadth/length ratio of fore-part 



Fusion of the keels 



Shape of the cephalic lobe 



Number of pairs of metameric 



papillae 

 Dimensions of the cuticular 

 plaques (ц) : 

 from the metameric papillae 

 from the nonmetameric papillae 

 from the papillae of the 

 zone of thickening 

 Shape of the cuticular plaques 

 on the papillae of the zone 

 of thickening 

 Segmentation of the tube 

 Maximum diameter of tube (mm) 

 Length of spermatophores (ц) 



17-18 



Oval 



+ 



0-22 

 400 



13-15 



Round 



0-17 



? 



40-45 



