POLYBRACHIA ANNULATA 



397 



Fig. 157 





С 



Fig. 158 



Fig. 157. Polybrachia annulata: Spermatophore. 



fil - filament of spermatophore ; m - base of filament. 



(After Ivanov, 1952.) 



Fig. 158. Polybrachia annulata: Tube: A - middle part; 

 В - a portion from about two-thirds back ; С - near the 

 hind end. (After Ivanov, 1952.) 



tapers into a long point, the other end is rounded and supports a delicate, 

 ribbon-like outgrowth, which always bends down at the base to run along one 

 of the flat sides of the spermatophore before tapering into the very long 

 slender filament. Excluding the ribbon-like outgrowth, the spermatophore is 

 0-6 mm long and has a maximum breadth of 0-17 mm. 



The very firm, opaque tube of P. annulata is brown or brown-black. The 

 length is not less than 50-60 cm and at the front end the diameter reaches 

 1-16 mm. The oldest narrowest part of the tube — the hind end — consists of 

 dark rings alternating with narrow clear intervals (Fig. 158C), but the greater 

 part of the tube is segmented, and each segment carries on its front edge a 

 filmy funnel-like frill or collar (Fig. 158^4), usually rather tattered. In the 

 middle part of the tube the segments have clear transparent irregular blotches, 



an - girdles ; с - cephalic lobe ; со - dorsal ciliated band ; da - front group of teeth ; dp - hind group 

 of teeth; f- keel of the bridle; go - genital papilla; gp - genital aperture; ms - mesosoma; 

 mts - metasoma; о - egg seen by transparency; p - articular plaque; pa - metameric papillae; 

 pa 1 - papillae of the zone of thickening ; pa 2 - postannular papillae ; ps - protosoma ; s 1 - groove 

 between the protosoma and the mesosoma ; s 2 - groove between the mesosoma and the metasoma ; 

 s 3 - pretentacular groove; sv - ventral sulcus; tc - tentacular crown. (E, F,G- after Ivanov, 1952.) 



O* 



