PREFACE. Vil 
obligations. ‘To my much-esteemed friend, Dr. John Flem- 
ing, Professor of Natural Science in the New College of 
Edinburgh, I owe much, not only for what instruction I 
have derived from his well-known publications, but for in- 
formation which I have received from his kind correspond- 
ence, without which I probably should never have entered 
on this department of study. To Dr. George Johnston, 
another much-valued friend, I need not say that I am spe- 
cially indebted, for almost every page of my book proclaims 
my obligations; and I hope it may prove a stepping-stone 
to his admirable volumes. To George Busk, Esq., of 
Greenwich, | return my grateful thanks, for not only giving 
me information and drawings, but for kindly superintend- 
ing the arrangement of the illustrations, and thus contri- 
buting much to the usefulness of the work. ‘To the Rev. 
Thomas Hincks, of Exeter, I am truly thankful for favour- 
ing me with a list of Devonshire Zoophytes, with specimens 
of the rarest of them, and for kindly permitting me to use 
his articles im the ‘Annals of Natural History’ respecting 
interesting Zoophytes which he has added to the British 
