THE 



CAMBRIDGE NATURAL HISTORY 



EDITED BY 



S. F. HARMER, M.A., Fellow of King's College, Cambridge ; Super- 

 intendent of the University Museum of Zoology 



AND 



A. E. SHIPLEY, M.A., Fellow of Christ's College, Cambridge; 

 University Lecturer on the Morphology of Invertebrates 



VOLUME III 



