CONTENTS 



Introduction page 187 



Methods 187 



Systematics 189 



General comparison with a typical Cypridinid 190 



Swimming and feeding 193 



Constitution and origin of dorsal body wall 195 



Endoskeleton and articulated sclerite system 200 



Blood system 212 



The pericardium and associated musculature 212 



The heart valves 217 



Blood vessels 219 



Nervous system 223 



General account 223 



Cardiac nervous system 228 



Basal ganglion system 230 



Visceral system 230 



Internal structure 233 



Excretory organs 235 



Summary 240 



Literature cited 243 



Plates XXXIX-XLII following page 244 



