HEPTABRACHIA CANADENSIS 



363 



The nonmetameric part of the preannular region of the trunk bears scattered 

 rounded papillae whose plaques differ neither in shape nor in size. Some- 

 what similar oval plaques of almost the same size (Fig. H144.F) lie on the tips 



0.5 



мм 



— s 



5 V — КЖЩ 



■sv 



€ 



20\l 



Fig. H144. Heptabrachia canadensis. A - the fore-part of the body from the ventral, B, from the 

 right and, C, from the dorsal side ; D - the ventral part of the keels of the bridle ; E - a plaque 

 from the metameric region of the trunk and, F, one from the zone of thickened papillae. 

 с - cephalic lobe ; со - dorsal ciliated band \f- bridle ; gp - genital papilla ; p - plaques ; pa - papillae ; 

 s 1 - groove between the protosoma and mesosoma ; x 2 - groove between the mesosoma and metasoma ; 

 s 3 , s* - secondary mesosomal grooves; sv - ventral sulcus; / - tentacle. (After Ivanov, 1962b.) 



