6 THE APODOUS HOI-OTHURIANS 



Page 



Physiology 61 



Motion 61 



Digestion and Absorption 63 



('irculation and Nutrition 63 



Kespiration 64 



Excretion 64 



Sensation 04 



Kegeneration 05 



Iieproduetion 66 



Ecology 66 



Taxology OS 



Key to the Subfamilies of Synaptida: 70 



Synaptiniu 70 



Euapta 72 



Oplieodesoma 73 



Polyplectana 76 



Synapta 78 



Synaptula 80 



Leptosynapta SO 



Labidoplax 94 



Protankyra 07 



Anapta 10!) 



Dactylapta Ill 



lihabdomolgus Ill 



Chiridotiuffi . . ., 112 



Chiridota 113 



Polycheira 120 



Tffiuiogyrus 121 



Trochodota 123 



Scoliodota 125 



Toxodora 125 



Achiridota 136 



]\Tyriotrochinae 127 



Myriotrochus 137 



Trochodenna 129 



Acanthotrochus 130 



Concluding Remarks on the Synaptida? 130 



Interrelationships 130 



Geographical Distribution 131 



Part IV. — The J[oi.vadiiii.t;. 



Morphology 135 



Form and Size 135 



Color 136 



Body-surface 136 



Tentacles 137 



Sense-organs 138 



Nervous System 138 



Body-wall 139 



Epidermis 139 



Connective-tissue Layer 140 



