^-.b'^r^ ^^ 



y:h 



THE 



CAMBRIDGE NATURAL HISTORY 



EDITED BY 



S. F. HARMER, Sc.D., F.R.S.. Fellow of King's College, Cambridge 

 Superintendent of the University Museum of Zoology 



A. E. SHIPLEY, M.A., F.R.S., Fellow of Christ's College, Cambridge 

 University Lecturer on the Morphology of Invertebrates 



