8 PREFACE. 



and from nature ; of the Echinoderms, from nature, 

 Agassiz, and Muller; of the Acalephs, from Agassiz; 

 of the Polyps, from Dana, Milne-Edwards, Verrill, 

 and from nature ; and of the Protozoans, mainly from 

 Ehrenberg and Huxley. 



Both this volume and the " Elements of Zoology " 

 already announced by Messrs. Scribner and Co., and 

 which will combine the study of the Anatomy and 

 Physiology of Animals with that of Descriptive 

 Zoology, are intended to precede the Manual men- 

 tioned above. 



Vassar College, Poughkeepsie, N. Y., 

 August, 1866. 



In the present edition a few changes have been 

 made, as the volume is no longer to be used in con- 

 nection with the Natural History Tablets. 



May, 1895. 



