8 PREFACE. s 



on Coral Beefs and Islands has been greatly extended by the 

 addition of facts from numerous sources. The authorities 

 cited from are stated in the course of the volume, and need 

 not here be re-mentioned. I have occasion, however, for special 

 acknowledgments to our excellent Yale Zoologist, Professor 

 A. E. Verrill, who now stands first in the country in the de- 

 partment of Zoophytes. Through bis recent memoirs on the 

 subject, and also by his personal advice, I have been greatly 

 aided in acquainting myself with the present state of the sci- 

 ence : — my own special labors in this branch of zoology having 

 ended in 1850, when both the Reports, referred to above, had 

 been published, and the last of my Expedition departments — 

 that of the Crustacea — forced my studies in another direction. 

 The illustrations of the following pages have been drawn 

 mainly from my Expedition Reports. Those not my own are 

 from the works or memoirs of Gosse, Mobius, Verrill, Pour- 

 taxes, L. Agassiz, A. Agassiz, Smitt, Edwards and Haime, 

 Wilkes, and Haett. In addition, the volume is indebted for 

 a few cuts to the beautifully illustrated popular works, " Le 

 Monde du Mer " and " La Vie et les Mceurs des Animaux; " 

 but nearly half of these were engraved from my plates. The 

 sources of all the figures are given in the List of Illustrations. 



James D. Dana. 

 New Haven, Conk., February 12, 1872. 



