AMBBIGAN SCIENCE SERIES— ADVANCED COURSE 



ZOOLOGY 



FOR 



HIGH SOHOOLf^ AND COLLEGES 



A^ PACKAED, M.D., Ph.D. 



ilEMBER pF T|^\wATIONAL ACADEMY OF SCIENCES; PROFESSOR OF ZOOLOGY 



AND GEOLOGY IN BROWN UNIVERSITY 



SEVENTH EDITION, REVISED 



NEW YORK 



HBNEY HOLT AND COMPANY 



1889 



