XXVI 



Due to minute waves of contraction of ventral surface or other 

 part of the body- wall, passing in the direction of motion, usually 

 from behind forwards. 



Animals, 



Examples. Anthozoa : Dianthus. 

 Bryozoa : Cristatella. 

 Gastropoda : Helix. 



Motion effected by extensions and contractions of the whole 

 body, a special process of it, or of successive segments. 



Examples. Annelida. 



Echinodermata : Asteroidea, &e. 



Pelecypoda. 



Ophidia. 



By loop action. The body being extended, the anterior end 

 is fixed ; the opposite extremity is then drawn up to it and fixed, 

 the body being looped ; the extension of the body and fixation 

 of the anterior end is then repeated. 



Examples. Hydrozoa : Hydra. 

 Annelida : Hirudo. 



Insecta : Larvae of Lepidoptera, Geometrina. 

 Gastropoda : Xenophora. 



By undulatory movements, or by appendages. 



Examples. Annelida. 



Reptilia : Ophidia. 



WALKING AND RUNNING. 



Body more or less raised on processes of the body, or jointed 

 limbs, which effect the locomotion by pulling, pushing, or 

 usually both. 



Examples. Infusoria: Hypotricha. 



Hydrozoa : Planoblast of Clavatella. 



Crustacea. 



Myriapoda. 



