450 PART II. SYSTEMATIC ACCOUNT 



The colour of the living female after removal from the tube was brick-red. 



The flattened, leaf-like spermatophore is very large (2-5 mm long by 

 0-35 mm broad at the widest part). One end is drawn out into a long, gradually 

 tapering point, while the other broader end forms a flat outgrowth from which 

 springs the rather stout filament (Fig. 173). The latter turns down at the 

 base to run along one of the flat sides of the spermatophore where it forms a 

 thick skein. The filament is very long and tapers gradually right up to the 

 very end. 



The tube has a smooth, somewhat lustrous surface and is a dark black- 

 brown colour (Fig. 170). In the female its diameter near the front end 

 reaches 2-8 mm, but fragments are known up to 3 mm across. 



Material: three specimens (two males and a female). 



Locality : the southwestern part of the Bering Sea. 



Depth: 3260 m. 



2. Spirobrachia beklemischevi Ivanov (Figs. 16, 174-6) 



Ivanov, 1957a: 474, 483-9, 490, 492-4, 496, Figs. 53-9; Ivanov, 1957b: 1139; Abri- 

 kosov, 1957: 238; Dajoz, 1958: 236; Ivanov, 1958b: 1687; Ivanov, 1960a: 1538, 1540, 

 1542, 1613, Figs. 1387, 1398, 1465, 1468; Ivanov, 1960c: 5, 10, 22, 23, 25, 92, 94, 97, 228, 

 254, 258-62, 266, Figs. 16, 84, 87, 174-6. 



The fore-part of the body is cylindrical and comparatively short, with a 

 length to breadth ratio of 2-2£ : 1 (Fig. 174Л, 5, C). The large, flattened 

 cephalic lobe is round in front. The bridle lies at the centre of the fore-part 

 of the body and its narrow brownish keels are situated on ridges which are 

 especially pronounced on the dorsal side (Fig. 11 4 A). The ventral ends of 

 the keels are somewhat club-shaped and do not meet, nor do the thinner 

 dorsal ends. A shallow median furrow runs along the ventral side of the fore- 

 part of the body, while a narrow dorsal furrow, broadening at its front end, 



Fig. 174. Spirobrachia beklemischevi: A - front end of a female from the ventral, and, В - from the 

 dorsal side ; С - front end of a male in ventral view ; D - pulvillus and plaque from a metameric 

 papilla ; E - pulvillus and plaque from the hind part of the metameric section of the metasoma ; 

 F - region of the girdles from the ventral, and, G - from the dorsal side; H - part of a girdle; 

 / - toothed platelet in side view. 



an - girdles; ax - ridge of the bridle; с - cephalic lobe; со - dorsal ciliated band; da - front teeth; 

 dp - back teeth;/- keel of the bridle; go - genital papilla; me - membrane of plaque; ns - nerve 

 furrow; p - cuticular plaques ; pa - metameric papillae ; pa 1 - non-metameric papillae ; pa 2 - papilla 

 lying behind the girdles ; pu - pulvillus ; s 2 - groove between the mesosoma and the metasoma ; 

 sv - ventral sulcus; tc - tentacular crown; te - external tentacle of the tentacular plate. (А, В, C, 

 D, E,F,G- after Ivanov, 1957a.) 



