Nichols, D. <br/><br/>
The animal kingdom ( motion picture) / 
speakers: D. Nichols, E. R. Trueman, M. E. Varley 
 - Milton Keynes :  Open University,  1972 
 - 1 film reel ( 23 min.) :  sd., b&w. ;  16 mm. + notes 
<br/><br/> Illustrate the theme of the unit text - that many animals move by means of'fluid muscle systems' and'hydroskeletons'.  Three internal cavities that can act as hydroskeletons are shown : enteron (in cnidrarian anemones), haemcroel (in bivalve molluscs); coelom (in echinoderm starfish) 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Animal locomotion<br/>Animal mechanics